14 research outputs found

    Foundation Settlement Determination: A Simplified Approach

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    The heterogeneous nature of the subsurface requires the use of factual information to deal with rather than assumptions or generalized equations. Therefore, there is need to determine the actual rate of settlement possible in the soil before structures are built on it. This information will help in determining the type of foundation design and the kind of reinforcement that will be necessary in constructions. This paper presents a simplified and a faster approach for determining foundation settlement in any type of soil using real field data acquired from seismic refraction techniques and cone penetration tests. This approach was also able to determine the depth of settlement of each strata of soil. The results obtained revealed the different settlement time and depth of settlement possible

    Attenuation Variability in Porous Media: Effects on Phase Delay and Quality Factor

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    Electromagnetic methods of surveying involve the propagation of time varying low frequency electromagnetic fields in and over the earth. This gives rise to a secondary electromagnetic field and a resultant field which is picked up by suitable receiving coil. This research work modelled electromagnetic method of survey using a Cathode Ray Oscilloscope and a signal generator. This work was aimed at relating the effects of phase delay and the quality factor of a propagating signal to some properties of the homogeneous medium, like porosity (compaction), permeability and hydraulic conductivity. River bed sand was used as the sample, it was washed, oven dried, sieved into different grain sizes and the porosity was determined. Each sample was packed in a square box and connected to a signal generator and an oscilloscope. Two sinusoidal waves of the same frequency, but different amplitudes were sent from a signal generator and the measurement was taken at different frequencies. Graphs of frequency were drawn each against phase delay and Q – factor. Graphs of porosity were drawn each against phase delay and Q – factor. In conclusion, we observed that the porosity of a material increased with the decrease in the mixture of its grain size and signals were more attenuated at lower frequencies but as the frequency of the input signal was increased, the material became more permeable to the passage of the input signal. Keywords: porosity, attenuation coefficient, phase delay, quality factor and electromagnetis

    RADIOLOGICAL RISKS OF RADIUM-226 ON GROUNDWATER BASED-DRINKING IN KUBWA AND GOSA AREA OF ABUJA , NORTH CENTRAL NIGERIA

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    The radiological risks associated with radium-226 in groundwater samples were analyzed using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The mean annual effective dose from the natural radionuclide of radium-226 (226R) was estimated to be 2.2 x 10‒5 mSv. In the groundwater samples, Lifetime average daily dose (LADD) ranged from 1 x 10‒3 to 2 x 10‒3 μg kg‒1 day‒1. The LADDs and the highest cancer mortality risk was found at Kubwa borehole with a value of 3.1 × 10‒8 and lower value reported at Gosa borehole with a value of 1.8 x 10‒8 . The highest cancer morbidity of 9.7 x 10‒9 was noted at Kubwa whereas lower value of 5.2 x 10‒9 reported at Gosa borehole. The radiological risks of 226Ra in the water samples were found to be low, typically in magnitude of 10−7. With this low level of radiological implications, it may be the chemical toxicity associated with 226Ra as a heavy metal. The values obtained in the study area may not pose radiological hazards to the residents that rely on groundwater. At the same time, measures of groundwater quality protection and monitoring should be enhanced and new supply source which has lower risk must foun

    Geochemical Analysis of Domestic Groundwater Sources in a Suburb of Ota, Southwestern Nigeria

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    Groundwater as one of the most valuable natural resources supports human health, economic development and ecological diversity. The activities of many constituents related to groundwater such as micro-organisms, gases, inorganic and organic materials can lead to contamination of well water, municipal drinking water sources and the environment. Therefore, geochemical analyses of domestic groundwater sources within Iju, Southwestern Nigeria have been conducted to determine the groundwater properties of water samples from available hand-dug wells and boreholes within the area. Fifteen (15) water samples sourced from wells and boreholes within the study area were analyzed for their major trace elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the laboratory and physiochemical characteristics such as pH, total dissolved solids and conductivity were calculated to determine the suitability of such water for agricultural and domestic consumption. The bulk analysis on the water samples revealed that majority of the trace elements when compared with the World Health Organization (WHO) drinking water standards and Acme Laboratory Canada Method Detection Limits (MDL) have values that agree with the recommended limit. These findings show that the present status of groundwater in Iju is good for domestic and agricultural purposes. However, the presence of trace elements such as Lead, Bromide, Copper, Potassium, Manganese, Rubidium and Silicon in fairly high quantities in the groundwater samples which may be as a result of treatment in the water or dissolved salts in the groundwater may constitute major health hazards if not quickly checked. In spite of groundwater studies done in Ota, important information on groundwater resources in Iju is still largely unavailable. Thus, groundwater management can be effectively planned based on these results for the stud

    Assessing the Life Average Daily Dose (Ladd) due to Heavy Metal Contents in Water Samples from Covenant University, Canaanland, Ota, South West Nigeria

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    The consumption of water with elevated concentration of lead (Pb) can prevent Hemoglobin Synthesis (Anemia) and results in Kidney diseases. A cross sectional study was conducted in to estimate the risk of exposure to lead via groundwater and bottled water ingestion pathway for the population of Covenant University, Canaanland, Ota, Ogun Sate using Perkin Elmer Optima 8000 ICP-OES. The concentration of Pb, Cr, Cd and As varies from water sample to another with the highest value of .7.07 ¹gL¡1 was noted in borehole water sample (BH1) behind John Hall. Comparing the value with the International recommended level by USEPA and WHO respectively, 7.07gL¡1is less than 15¹gL¡1 and 10 ¹gL¡1. The Life Average Daily Dose (LADD) estimated in this present study reported higher in BH1 for lead (Pb) and could pose health hazard if accumulated for a long time. This work suggest measures to employ quality water treatment plant to reduce the level of heavy metals in the selected water samples and also more research on radioisotopes in the same water sample

    Geochemical Analysis of Domestic Groundwater Sources in a Suburb of Ota, Southwestern Nigeria

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    Groundwater as one of the most valuable natural resources supports human health, economic development and ecological diversity. The activities of many constituents related to groundwater such as micro-organisms, gases, inorganic and organic materials can lead to contamination of well water, municipal drinking water sources and the environment. Therefore, geochemical analyses of domestic groundwater sources within Iju, Southwestern Nigeria have been conducted to determine the groundwater properties of water samples from available hand-dug wells and boreholes within the area. Fifteen (15) water samples sourced from wells and boreholes within the study area were analyzed for their major trace elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the laboratory and physiochemical characteristics such as pH, total dissolved solids and conductivity were calculated to determine the suitability of such water for agricultural and domestic consumption. The bulk analysis on the water samples revealed that majority of the trace elements when compared with the World Health Organization (WHO) drinking water standards and Acme Laboratory Canada Method Detection Limits (MDL) have values that agree with the recommended limit. These findings show that the present status of groundwater in Iju is good for domestic and agricultural purposes. However, the presence of trace elements such as Lead, Bromide, Copper, Potassium, Manganese, Rubidium and Silicon in fairly high quantities in the groundwater samples which may be as a result of treatment in the water or dissolved salts in the groundwater may constitute major health hazards if not quickly checked. In spite of groundwater studies done in Ota, important information on groundwater resources in Iju is still largely unavailable. Thus, groundwater management can be effectively planned based on these results for the study are

    Geochemical Analysis of Domestic Groundwater Sources in a Suburb of Ota, Southwestern Nigeria

    Get PDF
    Groundwater as one of the most valuable natural resources supports human health, economic development and ecological diversity. The activities of many constituents related to groundwater such as micro-organisms, gases, inorganic and organic materials can lead to contamination of well water, municipal drinking water sources and the environment. Therefore, geochemical analyses of domestic groundwater sources within Iju, Southwestern Nigeria have been conducted to determine the groundwater properties of water samples from available hand-dug wells and boreholes within the area. Fifteen (15) water samples sourced from wells and boreholes within the study area were analyzed for their major trace elements using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in the laboratory and physiochemical characteristics such as pH, total dissolved solids and conductivity were calculated to determine the suitability of such water for agricultural and domestic consumption. The bulk analysis on the water samples revealed that majority of the trace elements when compared with the World Health Organization (WHO) drinking water standards and Acme Laboratory Canada Method Detection Limits (MDL) have values that agree with the recommended limit. These findings show that the present status of groundwater in Iju is good for domestic and agricultural purposes. However, the presence of trace elements such as Lead, Bromide, Copper, Potassium, Manganese, Rubidium and Silicon in fairly high quantities in the groundwater samples which may be as a result of treatment in the water or dissolved salts in the groundwater may constitute major health hazards if not quickly checked. In spite of groundwater studies done in Ota, important information on groundwater resources in Iju is still largely unavailable. Thus, groundwater management can be effectively planned based on these results for the study area

    A study of natural radioactivity in some building materials in Nigeria

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    Building materials of different brands were assessed for the concentrations of 226Ra, 232Th and 40K using HPGe detector. The activity concentrations in the measured samples ranged from 27 ± 8 to 82 ± 8 Bq kg−1 for 226Ra, 41 ± 4 to 101 ± 8 Bq kg−1 for 232Th and 140 ± 8 to 940 ± 19 Bq kg−1 for 40K, respectively. The Radium equivalent (Raeq) activity from the samples was found to be <370 Bq kg−1 as the recommended value for construction materials. This study will set a baseline data for significant standards on radiation exposure of the measured radionuclides in the selected building materials used in Nigeria

    EVALUATION OF RADIOACTIVITY FROM COMMERCIAL CONSTRUCTION MATERIALS AND ITS RADON EXHALATION IMPLICATIONS ON RESIDENTS

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    The activity concentrations obtained from the measured samples were used to estimate the radiological risks of radium equivalent activity (Raeq) in the construction substance. The activity concentrations of few samples were found to exceed the international recommended points. But, the largest radium equivalent activity (Raeq) acquired from this research is less than the peak dose limit of one as stipulated by global recommendation. The correlation coefficient between the dose rate and Raeq activity indicated positive, revealing that increase in Raeq, enhances the dose exposure to the dwellers. Chi-square plot of Raeq activity against the samples revealed that royal ceramic tiles could be the most stable, having their raw materials (geologic material) components in equal and balanced proportions. It may also indicate that Royal ceramics has relationship with all other samples (as per composition). The whiskers indicate upper and lower quartiles, so the box spans the interquartile range. Qi = 115.66, median = 153.5, Q3 = 238, IQ = 122.34, whiskers = 115.66, 23

    Sustainable nano-sodium silicate and silver nitrate impregnated locally made ceramic filters for point-of-use water treatments in sub-Sahara African households

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    The poor access to water quality for Nigerians has pushed for the designing of new trend silver nitrate impregnated locally made Point-Of-Use (POU) ceramic filters to enhance water purification efficiency for household use. This study utilized silver nitrate-molded ceramic filters prepared with Kaolin from Owode, silt soil, sodium silicate, sawdust, and distilled water in three varying proportions to ascertain pollution removal efficiencies. Heating was carried out by firing the filters at 900 �C and further preheating at 400 �C after dipping in silver nitrate solution. Silver nanoparticle and dissociated particle discharge from filter pot painted with 0.03 mg/g caseincovered nAg or AgNO3 were estimated as an element of pH (5–9), ionic strength (1–50mM), and cation species (Naþ, Ca2þ, Mg2þ). Silver delivery was constrained by disintegration as Agþ and resulting cation exchange measures, paying little heed to silver structure applied. Water analysis for both heavy metals (Pb and Cd) and microbial load (E. coli) evaluated, corroborate the maximum removal efficiency. It was observed that kaolinsawdust with the Silver nitrate filters showed a constant and effective removal of both heavy metals and disinfection of microbial loads. The minimum flow rates observed were 4.97 mL/min for batch filter used for Iju River water sample one (AF1) and 4.98 mL/min for batch filter used for Iju River water sample two (AF2) having porosity 49.05% and 50.00%, whereas the 5 mL/min higher flow rate was used for batch filter from borehole water sample one (BF1) and batch filter used for well water sample two (CF2) with porosity of 50.00%. Significantly, the results obtained show that the filters are suitable for point-of-use application in both the urban and rural areas of developing countries such as Nigeri
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