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GIS and MATLAB modeling of criteria pollutants: A study of Lower Onitsha Basin during rains
Get PDFA research article with figures and tablesThe study of air pollutants SO2, NO2 and PM10 in lower Onitsha basin, a densely populated city was performed using GPS and Matlab modeling. The pollutants were studied in nine specific locations for 3 months of rains over 3 consecutive years with each georeferenced. The Matlab pollution model was generated by integrating the spatial database and measured pollution attributes database using a polynomial expression. SO2 highest concentration (141 µg/m3) peaked in Upper Iweka at sampling point 1 before dispersing to lower concentrated regions in Awada and Resthouse. NO2 peaked at 207 µg/m3 in Upper Iweka at sampling point 3 and driven by wind towards Borromeo area to very low concentration of 38 ug/m3.
The PM10 peaked in Upper Iweka (180 µg/m3) and driven by rains towards Borromeo before increasing again in concentration levels at Awada. The AQI showed that SO2 pollutants had acceptable air quality at all sampling points while NO2 and PM10 air quality affected sensitive groups. SO2 concentration levels exceeded the National air quality standard in Nigeria (NAQS) while NO2 and PM10 were below the NAQS standard. The GIS plot showed that 3 metrological forces were driving pollutants from Upper Iweka and Awada to other sampling areas in the order of SO2> NO2> PM10. The Matlab wind speed plot showed that there was an upward wind in upper Iweka driving the pollutants towards dispersal at some other region. Thus, Upper Iweka is an active point source pollution area and dispersed to Borromeo and Awada by scavenging rains under prevailing wind speed, wind direction and humidity. Hence calls for improved monitoring and regulation to address poll
Dynamics of Bank Lending and Credit Management
No full textThis book is all about critical issues on bank lending, and credit management. It also discussed issues that affect credit decisions in banks in a simplified manner
Physics 408: Electronic IV
No full textA lecture note which covers areas as Modulation and detection; amplitude
modulation: square law modulator and detector, switching modulator, envelope detector, double
sideband suppressed carrier (DSBSC) modulation, generation of balanced modulator, ring
modulation, coherent detector of DSBSC waves, double-balanced modulator; Single sideband
modulation (SSB) and demodulator; vestigial sideband modulation (VSB); frequency modulated
(FM) systems,; high frequency oscillators, high input impedance circuits
Establishing risk assessment from reclaimed Nekede Mechanic Village Owerri, Nigeria
Get PDFA research article with figures and tablesThe current resettlement of Nekede Auto-Mechanic village by Imo State government of Nigeria created a sparse piece of land awaiting government utilization. Risk assessment was carried out on the land using existing boreholes and soil to determine land utilization potential. Analysis of the physicochemical water parameters showed that there was no contamination of boreholes. The high value of COD correlated with the high levels of Fe in soil and water samples. Heavy metals concentrations showed that Fe was very much present in the soil while Pb, Cd and Cu had reduced concentrations. Risk assessment for the soil samples showed that Fe had the highest mean and median value. The highest mean value for water was Cu metal. Highest variance value was Cu in soil while Pb had the lowest value in water. Hazard quotient of water samples showed that hazards existed for Cd, Cu and Pb but at a moderate level for Fe. Estimated daily/weekly water intake values were all below WHO/FAO standards. The soil enrichment factor showed no enrichment for Pb, minimal enrichment for Cd, moderate enrichment for Cu and significant contamination for Fe. Ecological risk assessments for the heavy metals were at low ecological risk. Potential ecological index depicts Fe and Cd at a considerable level of ecological risk. Likewise, contaminants existed at the nearby Otamiri river due to dredging and nearby waste dumps. The anthropogenic activity at the Otamiri river posed a serious environmental concern if not controlled and reclaimed. Hence, the reclamation of Nekede auto mechanic village will not be suitable for agricultural or recreational purposes
Gas chromatography-spectrophotometric (GC- MS) studies on therapeutic potentials of costus afer ker gawl leaves
No full textThis article contain figures and tablesThe ethanol leaf extract of Costus afer was subjected to qualitative phytochemical screening, column chromatography and GC-MS analysis to ascertain the compounds that exhibit anti-inflammatory and anti-oxidant properties as claimed by herbalists and traditionalists. The presence of Flavonoids, Saponins, Steroids, Terpenoids and Anthraquinones were indicated in the phytochemical screening. Eluent fractions from the moderately polar solvent of the column chromatography generated Gas Chromatogram that had 6 prominent peaks indicated that the prevailing compounds were oxirane hexadecyl (4.09%), n-Hexadecanoic acid(3.68%), 9-octadecenoic acid (z)- methyl ester(3.08%), 6-octadecenoic acid (z)- (13.49%) and two pentacyclic compounds identified as Cycloursan-3-ol, acetate (36.17%) and lupenone (39.50%). The two pentacyclic compounds confirmed the presence of steroids and validates the use of C.afer leaf for anti inflammatory therapy and as an antidote for acute toxi
Mercerized milletia sp fiber epoxy composites: Fiber loading, aspect ratio and mechanical properties
No full textThe article contains tables and figureThe fiber loading capacity and poor adhesion between fibers and matrix remains an area of concern in fiber polymer composites. The fiber loading capacity and aspect ratio of mercerized milletia sp fiber on mechanical properties (tensile strength, tensile modulus, tensile toughness, elongation, flexural and impact strength) of Milletia sp fiber epoxy composites was investigated. Milletia sp fiber was extracted using water retting approach. The extracted fiber was mercerized at optimum treatment conditions of 5.84 wt% NaOH and 42.58mins. The epoxy composite samples were prepared using hand layup method for epoxy 103 and amine hardner in a ratio 2: 1 and commingled with untreated and treated fiber, respectively, at optimum treatment conditions. The fiber loading of 10 – 50 wt% and aspect ratio of 42.68 – 213.38 mm/mm were used. The mechanical properties of mercerized milletia sp fiber epoxy composite were determined and optimized using RSM of MATLAB statistical tool box. The tensile strength, tensile modulus, toughness, elongation, flexural strength and impact strength for epoxy resin was 44.2 MPa, 1.9716 GPa, 0.8177 MPa, 3.1%, 85.4 MPa and 360 Kj/m2, respectively. At optimum aspect ratio and fiber loading, the mercerized milletia sp fiber increased the tensile strength, tensile modulus, toughness, elongation, flexural strength and impact strength of the epoxy resin by 46.38, 77.75, 97.99, 18.81, 125.06 and 217.78%,
respectively. Thus, mercerized Milletia sp fiber enhanced the mechanical properties of epoxy composites
Radiation levels around some X-ray diagnostic centres in Owerri, Imo State, Nigeria
Get PDFA resource article with figures and tablesRadiation levels were measured around eight diagnostic centres in Owerri, Imo State Nigeria using a portable Geiger Muller counter model GCA-04. The measurements were taken when the radiation sources (x-ray machines) were operational and non-operational. When the machines were non-operational, the background radiation ranged from 0.63 to 1.48 mSv/yr. When the machines were operational, the radiation levels ranged from 0.82 to 24.28 mSv/yr; this adds between 0.19 to 23.14 mSv/yr to the existing background radiation. The diagnostic centres used in this work have background radiation level below the world average dose limit of 2.16 mSv/yr for natural background radiation. Seven centres had annual dose rates that were below the 1.25mSv/yr dose limit for the public when the radiation source is not on and only one centre had a value still below the dose limit for the public when the radiation source was
on. The other centres had higher values of annual dose rate when the safety of the general public is considered both for the cases when the radiation source was operational and non-operational
Studies on adsorptive behavior of Cd2+ on graphene oxide: Alternative novel approach
Get PDFThis is an original research article with figures and tablesCertain adsorptive mechanisms and interactions often exist within linearized kinetic functions which are largely unreported. A novel inverse saturation modeling was applied to evaluate the adsorptive behavior of super-saturation, saturation, and desorptive processes on linear kinetic function plots using pseudo 1st order, pseudo 2nd order, Elovich and Intra-particle diffusion. Graphene oxide was prepared by room temperature synthesis and used as adsorbent over Cd2+ adsorbate. Batch adsorption process was conducted and four error functions were utilized. The sum of squares of the errors and Sum of absolute errors identified pseudo 2nd order as having the least deviation at 0.113 and 0.337 respectively. The modelled pseudo 1st order reaction had R2 = 0.985 while the inverse saturation model had R2 value of 0.998, both been a better data fit than non-modelled pseudo 1st order R2 at 0.917. The slower reaction kinetics in pseudo 1st order was due to supersaturation during adsorption as shown by inverse saturation point. The correlation coefficient of modeled kinetic plot of pseudo 2nd order, Intra particle diffusion and Elovich had R2 = 1. The Elovich inverse saturation plot showed that the graph was an L-isotherm type indicating progressive saturation. The rate determining step experienced by Intra-particle diffusion was accommodated by wide range of inverse saturation plots showing adsorption, supersaturation and desorption as points of greatest influence. The inverse saturation plot of pseudo 2nd order plot had absolute slope of 2.656 and large intercept of 24.815 driving it's faster reaction kinetics. Hence, the inverse saturation point modelling provided a much better interpretation of adsorptive behavior of graphene oxide adsorbent over Cd2+ adsorbate