52 research outputs found
Petrophysical and rock physics analyses for characterization of complex sands in deepwater Niger delta, Nigeria
Characterization of complex sand reservoirs in deepwater of Niger Delta was carried out through petrophysical and rock physics evaluation of well log data from three wells. Petrophysical analysis to determine clay volume, porosity, lithologies and hydrocarbon saturation were made. Rock physics was studied in velocity-porosity plane to analyze the influence of depositional and diagenetic features on the reservoirs. Cross-plots of different elastic parameters, using linear regression and cluster analysis, were generated for lithologic and fluid fill identification and to differentiate between the hydrocarbon bearing sands, brine sands and shale. Variance attribute was extracted on seismic time slice in order to image the complex sand distribution in the area. Three reservoirs of turbidite origin were identified within the upper fan to lower fan area. Petrophysical results revealed gas bearing reservoir units with less than 20% shale volume and porosity of 25-31%. Lambda-Mu-Rho (LMR) cross-plots for the reservoirs show gas saturated data cloud and trend. Ratio-Difference (R-D) cluster analysis of elastic rock properties shows a distinct trend and data cloud that represents lithofacies units and fluid fills. The study concludes that the reservoirs simulated contact cement and friable models with properties that ranged from highly porous, well sorted and poorly consolidated sand to fairly sorted and highly cemented sands. The results provide a model that increases the possibility of finding reservoir sand, while mitigating the risk involved in finding hydrocarbons
Petrophysical and rock physics analyses for characterization of complex sands in deepwater Niger delta, Nigeria
Characterization of complex sand reservoirs in deepwater of Niger Delta was carried out through petrophysical and rock physics evaluation of well log data from three wells. Petrophysical analysis to determine clay volume, porosity, lithologies and hydrocarbon saturation were made. Rock physics was studied in velocity-porosity plane to analyze the influence of depositional and diagenetic features on the reservoirs. Cross-plots of different elastic parameters, using linear regression and cluster analysis, were generated for lithologic and fluid fill identification and to differentiate between the hydrocarbon bearing sands, brine sands and shale. Variance attribute was extracted on seismic time slice in order to image the complex sand distribution in the area. Three reservoirs of turbidite origin were identified within the upper fan to lower fan area. Petrophysical results revealed gas bearing reservoir units with less than 20% shale volume and porosity of 25-31%. Lambda-Mu-Rho (LMR) cross-plots for the reservoirs show gas saturated data cloud and trend. Ratio-Difference (R-D) cluster analysis of elastic rock properties shows a distinct trend and data cloud that represents lithofacies units and fluid fills. The study concludes that the reservoirs simulated contact cement and friable models with properties that ranged from highly porous, well sorted and poorly consolidated sand to fairly sorted and highly cemented sands. The results provide a model that increases the possibility of finding reservoir sand, while mitigating the risk involved in finding hydrocarbons
Integrated geotechnical and geophysical investigation of a proposed construction site at Mowe, Southwestern Nigeria
The subsurface of a proposed site for building development in Mowe, Nigeria, using Standard Penetration Test (SPT), Cone Penetrometer Test (CPT) and Horizontal Electrical Profiling (HEP), was investigated with the aim of evaluating the suitability of the strata for foundation materials. Four SPT and CPT were conducted using 2.5 tonnes hammer. HEP utilizing Wenner array were performed with inter-electrode spacing of 10 – 60 m along four traverses coincident with each of the SPT and CPT. The HEP data were processed using DIPRO software and textural filtering of the resulting resistivity sections was implemented to enable delineation of hidden layers. Sandy lateritic clay, silty lateritic clay, clay, clayey sand and sand horizons were delineated. The SPT “N” value defined very soft to soft sandy lateritic (<4), stiff silty lateritic clay (7 – 12), very stiff silty clay (12 - 15), clayey sand (15- 20) and sand (27 – 37). Sandy lateritic clay (5-40 kg/cm2) and silty lateritic clay (25 - 65 kg/cm2) were defined from the CPT response. Sandy lateritic clay (220-750 Ωm), clay (< 50 Ωm) and sand (415-5359 Ωm) were delineated from the resistivity sections with two thin layers of silty lateritic clay and clayey sand defined in the texturally filtered resistivity sections. Incompetent clayey materials that are unsuitable for the foundation of the proposed structure underlain the study area to a depth of about 18m. Deep foundation involving piling through the incompetent shallow layers to the competent sand at 20 m depth was recommended
Functional Tax Governance Apparatus and Economic Development
The proportion of tax earnings to gross domestic product (GDP) in Nigerian economy had been ranked and affirmed the least in the sub-Sahara African and as evolving economy, different reasons attested to this fact, hence, the study is aimed at investigate the inherent lacuna of tax governance apparatus in responses to economic development as broad objective. The study employed field research design, the research instrument that was deployed for collection of data is purposive and structured questionnaire targeted at elicit information from relevant and related stakeholders in tax matters, the research instrument and data collected were subjected to Cronbach alpha test and heteroscedasticity test to affirm the validity/reliability and best linear unbiased estimator of data collected respectively. The result revealed that the responsiveness of economic development to tax assessment, tax policy and tax administration were statistically significant inversely related while tax collection was statistically insignificant related directly with economic development. Thereby study concluded that poor management and administration of tax system in Nigeria responsible for adverse relationship that subsist between the proportion of tax earnings to GDP and resulted decayed and declined physical infrastructures and socio
Excessive oral intake caffeine altered cerebral cortex histoarchitecture and cell morphologies in adult mice
Caffeine is commonly consumed in an effort to enhance speed in performance and wakefulness. However, little is known about the deleterious effects it can produce on the brain, this study aimed at determining the extents of effects and damage that can be caused by excessive consumption of caffeine on the cerebral cortex of mice models with a view to examining caffeine effects on cerebral cortex histoarchitecture and cell morphologies. Twenty adult mice were used for this study. They were randomly divided into 4 groups of 5 animals each. Control rats were administered normal saline, experimental groups received caffeine through oral cannula at 10, 50 and 120 mg/kg body weight for 28 days to determine effects of graded doses of caffeine administration. The dosage of the caffeine selection was based on previously published work. The result indicates that at low and medium doses of caffeine administration, features of prominent eosinophilic cytoplasm with or without shrunken nuclei was observed in plates 1B, 1C, and 3B, 3C. And at high dose, features of degenerating neurons such as pyknotic nuclei and sparse neuronal population were observed in plates 2D and 3D when compared to the normal appearance of the neurons and the glial cells. In conclusion, low and medium doses of caffeine induced mild changes in cortical neuron morphology and at higher dose of caffeine administration, neurodegenerative changes were observed in cerebral histoarchitecture. This shows that at high dose, caffeine consumption can produce detrimental effects on brain structure as well asfunction in adult mice models.Key Words: Caffeine, histoarchitecture, neuropil, cortical neuron
Sphingomonas paucimobilis septicaemia in a tertiary care hospital in Nigeria: a case report
Sphingomonas paucimobilis is an opportunistic pathogen that occurs naturally in the environment. It has been implicated in both community acquired and healthcare associated infections. Sphingomonas paucimobilis septicaemia is commonly associated with contamination from the environment, the use of hospital and laboratory equipment, indwelling urinary catheters and intravenous cannula. Literature search for Sphingomonas paucimobilis septicaemia revealed several case reports documented globally with only a single case report from Nigeria detected by VITEK 2. We report a case of Sphingomonas paucimobilis septicaemia in 38-year-old unbooked 21 woman, P1+2(1A), admitted into the accident and emergency unit of Lagos University Teaching Hospital, Lagos, Nigeria, with complaints of fever, abdominal pain and distension, generalized body pain and difficulty in breathing, of six days post Caesarean section. Blood culture yielded Sphingomonas paucimobilis. Antibiotics were commenced at admission and exploratory laparotomy done seven days post presentation. However, patient died on day fourteen due to cardiopulmonary arrest
Irrigation and Nutrient Management for Crop Production: Maize (Zea mais) Performance, Resource Use Efficiency and Temporal Variability of Some Soil Properties
Information on soil health and nutrient management is crucial for recommending appropriate management practices for effective crop production and optimum yield. This study evaluated the effect of drip irrigation and fertilizer application on soil hydro-physical properties, performance and resource use of maize (Zea mais) in southwestern Nigeria. The experiment was a two factorial laid out in randomized complete block design (RCBD) and three replications. Irrigation treatment constituted the main factor namely: 100% (full irrigation), 75%, 50% and 35% of crop water requirement designated as 1.0IE; 0.75IE; 0.5IE and 0.35IE, respectively while the sub-plot was N-fertilization as N0 - no fertilizer application and N100 –100 kg Urea ha-1. The highest evaporation from the soil surface was obtained from the treatment that received full irrigation. At harvest, irrigation regimes and fertilizer rates significantly increased bulk density (BD) and soil water content (SWC) while saturated hydraulic conductivity (Ksat) decreased. The highest grain yield (3.5 tons ha-1) was obtained under full application of crop water requirement, about 28% greater than the yield obtained from water deficit (0.35IE) treatment. Nitrogen application of N100 gave higher grain yield compared to no fertilizer application. The interaction between drip irrigation and N-fertilization was significant on growth parameters, yield and water use efficiency (WUE) of maize. The study showed that soil hydro-physical properties were significantly influenced by drip irrigation while the combination of full irrigation water application (1.0IE) and adequate N-fertilization (100 kg N ha-1) is the best option for optimum maize performance and resource use efficiency. Keywords: Crop evapotranspiration, irrigation scheduling, soil hydro-physical properties, crop performance, resource use efficiency
Comparative studies of serum neuraminidase, free and erythrocytes surface sialic acid, packed cell volume and haemagglutination inhibition antibodies of chickens vaccinated with different Newcastle disease virus vaccines
Comparative studies of serum neuraminidase, free and erythrocytes surface sialic acid, packed cell volume
and haemagglutination inhibition antibody titres were carried out on a total of seventy-five Shaver Brown chickens
that were vaccinated with different Newcastle disease virus (NDV) vaccines. Trial birds were primed with NDV
Hitchner B1 vaccine prior to NDV La Sota and NDV Komarov vaccines administration. Twenty-five chickens
received NDV La Sota vaccine; a further 25 were vaccinated with NDV Komarov vaccine, while 25 chickens
served as control. The values of neuraminidase activity (NA), free serum sialic acid (FSSA), erythrocytes surface
sialic acid (ESSA) concentration, packed cell volume (PCV) and haemagglutination inhibition (HI) antibody
titres were determined sequentially for each chicken. The highest daily mean HI antibody titres of log2 7.12 ±
1.20 and log2 8.98 ± 1.73 were obtained from chickens vaccinated with NDV La Sota vaccine and NDV Komarov
vaccine, respectively, by day 15 post-vaccination (pv). Neuraminidase activity and FSSA concentration increased
gradually from days 1 to 5 pv in the two groups of chickens. In general, the period of increased NA and FSSA
concentration coincided with the time of a decline in values of ESSA and PCV in the two vaccinated groups of chickens. It was concluded that chickens which received NDV Komarov vaccine had higher daily mean values of NA, FSSA and HI antibody titres than their counterparts which received NDV La Sota vaccine
Učinak nekih inhibitora na neuraminidazu soja Kudu 113 virusa newcastleske bolesti.
A total of two hundred samples from dialysed neuraminidase of Newcastle disease virus (NDV) Kudu 113 strain were used for the experiment. Fifty samples each were used for various concentrations of paranitrophenyl oxamic acid (PNPO), salicyl oxamic acid (SOA), silver nitrate (AgNO3) and ethylene diamine tetra acetic acid (EDTA), to test their inhibition effects on the neuraminidase activity of NDV Kudu 113 strain in vitro, using thiobarbituric acid assay method. Of these inhibitors, AgNO3 had the highest inhibition effect on the neuraminidase activity of NDV Kudu 113 strain. Silver nitrate reduced the activity of this enzyme from 140.24 μMol/min for enzyme without AgNO3 to 32.36 μMol/min when AgNO3 was added to the enzyme at a concentration of 0.47 M. Paranitrophenyl oxamic acid had the least inhibition effect on the neuraminidase activity of NDV Kudu 113 strain at a concentration of 0.12 M. This inhibitor reduced the activity of the enzyme from 97.08 μMol/min for enzyme without PNPO to 91.70 μMol/min when PNPO was added to the enzyme at a concentration of 0.12 M. Ethylene diamine tetra acetic acid and SOA also greatly inhibited the activity of this enzyme. Salicyl oxamic acid reduced the activity of NDV Kudu 113 strain neuraminidase from 140.24 μMol/min for enzyme without SOA to 59.33 μMol/min when SOA was added at a concentration of 0.47 M. Similarly, EDTA reduced the activity of this enzyme from 124.06 μMol/min forenzyme without EDTA to 75.51 μMol/min when EDTA was added to the enzyme at a concentration of 0.35 M. In all the inhibitors examined, it was observed that their effects on the activity of NDV Kudu 113 strain neuraminidase increased as the concentrations of the inhibitors increased. It was concluded that PNPO, SOA, EDTA and AgNO3 inhibited the neuraminidase activity of NDV Kudu 113 strain in vitro. Therefore, further studies are needed to see if these inhibitors could be of use, after proper clinical trials, as potential agents for reducing Newcastle disease (ND) infections in poultry.Iz soja Kudu 113 virusa newcastleske bolesti pripremljeno je 200 uzoraka dijalizirane neuraminidaze u svrhu istraživanja inhibicijskog učinka različitih koncentracija paranitrofeniloksaminske kiseline, saliciloksaminske kiseline, srebrnog nitrata i etilendiamintetraoctene kiseline. Učinak svake navedene tvari istražen je na 50 uzoraka neuraminidaze postupkom koji se izvodi pomoću tiobarbiturne kiseline. Najveći inhibicijski učinak na aktivnost neuraminidaze imao je srebrni nitrat. On je u 0,47 M koncentraciji smanjio učinak enzima sa 140,24 μM/min na 32,36 μM/min. Para-nitrofeniloksaminska kiselina imala je najslabiji inhibicijski učinak na neuraminidaznu aktivnost pretraživanog soja. Ona je u 0,12 M koncentraciji smanjila aktivnost neuraminidaze s 97,08 μM/min na 91,70 μM/min. Za etilendiamintetraoctenu kiselinu i saliciloksaminsku kiselinu utvrđena je visoka inhibicijska sposobnost. Saliciloksaminska kiselina u 0,47 M koncentraciji smanjila je aktivnost neuraminidaze sa 140,24 μM/min na 59,33 μM/min. Etilendiamintetraoctena kiselina u 0,35 M koncentraciji smanjila je aktivnost enzima sa 124,06 μM/min na 75,51 μM/min. Inhibicijska aktivnost svih enzima povećavala se s njihovom koncentracijom. Zaključuje se da su sve rabljene tvari in vitro zakočile neuraminidaznu aktivnost soja Kudu 113 virusa newcastleske bolesti. Potrebna su daljnja istraživanja za njihovu moguću praktičnu primjenu u sprečavanju newcastleske bolesti
Effect of Drip Irrigation Frequency and N-Fertilization on Soil Physical Properties, Yield and Water Use Efficiency of Cucumber (Cucumis sativus L) in Ado Ekiti, Southwestern Nigeria
Soil water budgets are essential in determining the proper timing and amount of optimal irrigation for improving water and nutrient use efficiency in vegetable production A field experiment was therefore setup at the Teaching and Research Farm, Faculty of Agricultural Sciences, Ekiti State University, Ekiti State, Nigeria during 2015 dry season to evaluate the effect of drip irrigation frequency and N-fertilization on soil physical properties, yield and water use efficiency of cucumber (Cucumis sativus). The experiment was a 3x2 factorial in randomized complete block design, with split-plot arrangement in three replications. The main block consisted of three levels of drip irrigation frequency: daily water application (ID), twice weekly water application (I2W) and weekly water application (IW) while the sub-plots were nitrogen fertilization (No fertilizer (N0) and 80 kg N ha-1 (N80)). The results showed that soil bulk density (BD) and water content (SWC) of the 0-10 cm surface layer increased with time and was significantly highest from ID treatment compared with other treatments. N-fertilization had no influence on both BD and SWC whereas cucumber yield was significantly (p<0.05) increased. Reducing the frequency of water application increased cucumber water use efficiency (WUE) whereas N-fertilization had no significant effect on WUE. The different drip irrigation levels caused distinct spatial patterns of SWC and BD. The study showed that cucumber fruit yield will increase with more availability of water as well as good soil structural condition. However, for optimum yield, water saving strategy, reduced cost of pumping and lesser effect on soil structure, drip irrigation scheduling of twice weekly (I2W) combined with N-fertilization is recommended for cucumber cultivation. Keywords: Drip irrigation frequency, soil physical properties, spatio-temporal variability, cucumber yield, water use efficienc
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