Multiple Linear Regression Models For Estimating True Subsurface Resistivity From Apparent Resistivity Measurements

Multiple linear regression (MLR) models for rapid estimation of true subsurface resistivity from apparent resistivity measurements are developed and assessed in this study. The objective is to minimize the processing time required to carry out inversion with conventional algorithms. The arrays considered are Wenner, Wenner-Schlumberger and Dipole-dipole. The parameters investigated are apparent resistivity ( a ), horizontal location (x) and depth (z) as independent variable; while true resistivity ( t ) is dependent variable

Mediating Role of Customer Satisfaction between Service Quality and Customer Loyalty with Non-Interest Bank in Nigeria

The world has become a global village as competition among banks is now intense. Globalization is fuelling increased competition in Nigerian banking industry and as a result, banks are challenged to adopt customer centred strategies that would enable them to gain customer loyalty, maximize profitability and survive the competition. There is no business that survives without customers’ patronage and Islamic banks are not an exception. Customers are key stakeholders to the survival of any business, thus, satisfying the customer through providing high quality services is core to Islamic banking business. The aim of the study is to examine the mediating role of customer satisfaction in investigating the relationship between service quality and customer loyalty in non-interest bank i.e. Jaiz Bank of Kano state metropolis, Nigeria. The variance based (SEM) technique is employed in analyzing the hypothesized model of the study. Service quality positively and significantly influences customer satisfaction and customer loyalty, whereas, customer satisfaction does not significantly mediate the relationship between service quality and customer loyalty among customers of Jaiz bank in Kano state metropolis, Nigeria. The study recommends for providing high quality service in order to achieved maximum loyalty from the customers. It was further recommended on the need for reviving of the existing regulatory bodies or institutions that will ensure proper implementation of good service quality delivery among non-interest banks in Nigeria

Molecularly imprinted polymeric materials for adsorptive removal of nitrogen compounds from fuel oils

The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organonitrogen compounds (quinoline, carbazole and its alkylated derivatives) are such that they emit NOx to the environment when combusted, thereby reducing air quality. These compounds also deactivate the catalyst used during fuel refinement and in catalytic converters of cars. Hydro-denitrogenation (HDN), a process currently being employed in petroleum refineries to eliminate organonitrogen compounds in fuels, is limited in treating these refractory compounds. Hence, this thesis describes the use of two separate complimentary approaches for the removal of organonitrogen compounds in fuel such as oxidative denitrogenation and adsorptive denitrogenation. The catalyzed oxidation of fuel oil model nitrogen containing compound, quinoline to quinoline N-oxide, was conducted under batch and continuous flow microreactor at 70°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant and silica supported V2O5 as catalyst, followed by the selective adsorption of the quinoline N-oxide. An overall conversion of 62% quinoline N-oxide was observed. Quinoline-N-oxide in model fuel was absorbed by employing synthesized molecularly imprinted 2,6-pyridine-polybenzimidazole (2,6-PyPBI) nanofibers, 86% of quinoline-N-oxide was removed to give an adsorption capacity (qe) of 4.8 mg/g. DFT calculations to study the interactions of quinoline-N-oxide vs 2,6-PyPBI indicated that: (i) hydrogen bonding (through amino group of 2,6-PyPBI and oxygen atoms of the quinoline-N-oxide), (ii) pi-pi stacking and (iii) extensive number of van der Waals interactions took place. Several oxygenates from N-compounds were produced, thus, complicating the fuel matrix. Therefore, there is a need to move towards adsorptive denitrogenation. Poly-2-(1H-imidazol-2-yl)-4-phenol (PIMH) imprinted microspheres was prepared by suspension polymerization using 2-(2’-hydroxy-4-ethenylphenyl) imidazole as a functional monomer and ethylene glycol dimethacrylate as a crosslinker in the presence of various organonitrogen compounds (templates) to produce 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH). Imprinted microspheres show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 6.8 ± 0.2 mg/g, 6.3 ± 0.3 mg/g and 5.8 ± 0.3 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of quinoline (αi-r = 136.9) ˃ pyrimidine (αi-r = 126.2) ˃carbazole (αi-r = 86.3), when naphthalene was selected as a reference compound. Though, imprinted microspheres displayed excellent nitrogen compound removal both in model and real fuel, there was a need to improve the adsorbent adsorption capacity for N-compounds in fuel through the fabrication of imprinted nanofibers. Molecularly imprinted poly-2-(1H-imidazol-2-yl)-4-phenol nanofibers was prepared by electrospinning of 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH) in the presence of various organonitrogen compounds. These imprinted nanofibers show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 11.7 ± 0.9 mg/g, 11.9 ± 0.8 mg/g and 11.3 ± 1.1 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 258.8) ˃ quinoline (αi-r = 235.5) ˃ carbazole (αi-r = 168.2). It further displayed excellent nitrogen removal in real fuel. The use of polybenzimidazole (PBI) nanofibers showed selective adsorption of organonitrogen compounds as imprinted sorbent also displayed high selectivity for their target model nitrogen-containing compounds with adsorption capacities of 11.4 ± 0.4 mg/g, 11.9 ± 0.2 mg/g and 10.9 ± 0.7 mg/g for quinoline, pyrimidine and carbazole respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 241.5) ˃ quinoline (αi-r = 237.6) ˃ carbazole (αi-r = 170). Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed that quinoline-PIMH/PBI and pyrimidine-PIMH/PBI interactions are exothermic in nature, while carbazole-PIMH/PBI is endothermic in nature. DFT calculations indicated that π-π interactions/stacking and hydrogen bond interactions took place between N-compounds (carbazole, quinoline and pyrimidine) and adsorbent (PIMH and PBI). A significant reduction in the quantity of nitrogen containing compounds in hydrotreated fuel was observed (peak area reduction) when adsorbents (PIMH and PBI) was employed, however, the complex nature of organonitrogen compounds in fuel complicate the structure/function approach on MIPs for targeting these unwanted compounds

Synthesis and evaluation of the efficacies of some Schiff bases for the removal of heavy metals from wastewater

The Schiff bases, 2-aminoethyl-1,3-diphenyl-3-((2-(piperazin-1- ylethyl) imino) propylidene)-propylethane-1,2-diamine with 89% yield, and 2,2-ethylideneamino)ethyl)phenol-2,2- hydroxybenzalidene) ethyl)acetimedate salt with 91% yield, represented as L1 and L2 respectively were synthesized and characterized. Their metal ion removal competences for five heavy metals (Cu, Fe, Co, Cd and Pb) was investigated, in three categories of wastewater obtained from Lambun Dan Lawal (LDL), Kofar sauri (K/sauri) and Youth Craft Village (YCV). The Schiff bases were characterized before and after complexation, by spectroscopic techniques such as Infrared spectroscopy, Molar conductance, UV-Visible, Melting and Decomposition temperature and solubility test. The concentration of the heavy metals both in the wastewater and the complexes was determined by Atomic Absorption Spectroscopy (AAS). The Schiff bases shows outstanding character, by adsorbing/removing most of the targeted heavy metals at variable concentration, especially copper which shows the highest concentration. The results suggested that, the two Schiff bases can be used as an alternative chelating agents, for the removal of heavy metals from wastewater.Keywords: Schiff base, Wastewater, Heavy metals, Evaluation, Extractio

Performance Evaluation for an Optimized Wenner (ALPHA, BETA, AND GAMMA) Arrays Using Synthetic Geological Models

The study aimed at comparing the resolution and effectiveness of three-electrode arrays (Wenner-α, Wenner-β, and Wenner-γ) in the 2D Electrical resistivity method using Numerical analysis of geological models. Three synthetic geological models that simulate block-one dyke and water layer were generated using RES2DMOD software. The inversion used for the geological models was based on smoothness-constrained least-square inversion which was carried out with RES2DINV. The inversion results were imputed into surfer11 software to examine the image resolution, thereafter absolute percentage error (APE) was calculated to measure the effectiveness of the arrays. The result for the block-one model shows that the Wenner-β array has an APE of 14.45%, the Wenner-α array has an APE of 32.67%, and the Wenner-γ array with an APE of 29.15%. Similarly, for the dyke model, the Wenner-α array, Wenner-β array, and Wenner-γ array have an APE of 69.61%, 57.43%, and 45.49% respectively. However, the results for the water layer model show that the Wenner-α array has an APE of 17.11%, the Wenner-β array has an APE of 12.16%, and that the Wenner-γ array has an APE of 16.21%.  Wenner-α is expected to produce an image with the best resolution having the highest APE, henceforth APE suggests the resolution capacity of an array

Radiological and Toxicity Impact of Uranium (U-238) in Ground Water to Different Age Groups at Wurno, Sokoto State, Nigeria

One of the primary goals of the World Health Organization (WHO) is for every society to have an adequate supply of safe drinking water. This work aimed to assess the radiological and toxicity impact of ground water of Wurno Local Government Area. Uranium activity concentration from 45 water samples collected from different locations in the study area were determined using HpGe   detector, the result from the analysis was used to evaluate the annual effective dose due to ingestion of groundwater from the study area by the inhabitants.  Radiological and chemical toxicity risks were also calculated. High level activity was reported in Diggim while low activity level was reported in Nassarawa-Daje. The annual effective doses for adult, children and infants were estimated to be from 0.008 mSvy-1 to 0.32 mSvy-1. The highest risk cancer mortality value was found at Diggim with a value of 4.34 × 10-4 while the lowest value was observed at Nassarawa Daje with a value of 1.17 × 10-5. Chemical toxicity value ranged from 0.59 – 21. 79 µg.kg-1.day-1 with an average dose value of 5.12 µg.kg-1.day-1. The lifetime average daily dose (LADD) values were reported to be higher at Diggim and lower at Nassarawa-Daje with the values 21.79 µg.kg-1.day-1 and 0.59 µg.kg-1.day-1 respectively compared with 0.6 µg.kg-1.day-1 WHO limit standard. Significantly, the high activity level, and chemical toxicity risk reported from this study is an indication that the area may have developed some fractures of granitic strata in the subsurface geology that contributed to the wide distribution of radiation dose

Transmission dynamics of monkeypox virus in Nigeria during the current COVID-19 pandemic and estimation of effective reproduction number

Monkeypox virus (MPXV) continues to pose severe threats to global public health, especially in non-endemic areas. Like all other regions, Africa faces potential public health crises due to the ongoing COVID-19 pandemic and other infectious disease outbreaks (such as Lassa fever and malaria) that have devastated the region and overwhelmed the healthcare systems. Owing to the recent surge in the MPXV and other infections, the COVID-19-control efforts could deteriorate and further worsen. This study discusses the potential emergencies of MPXV transmission during the current COVID-19 pandemic. We hypothesize some of the underlying drivers that possibly resulted in an increase in rodent-to-human interaction, such as the COVID-19 pandemic’s impact and other human behavioral or environmental factors. Furthermore, we estimate the MPXV time-varying effective reproduction number ([Formula: see text]) based on case notification in Nigeria. We find that [Formula: see text] reached a peak in 2022 with a mean of 1.924 (95% CrI: 1.455, 2.485) and a median of 1.921 (95% CrI: 1.450, 2.482). We argue that the real-time monitoring of [Formula: see text] is practical and can give public health authorities crucial data for circumstantial awareness and strategy recalibration. We also emphasize the need to improve awareness programs and the provision of adequate health care resources to suppress the outbreaks. These could also help to increase the reporting rate and, in turn, prevent large community transmission of the MPXV in Nigeria and beyond

Efficient catalytic reduction of 4-Nitrophenol using Copper(II) complexes with N,O-chelating schiff base ligands

The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride was used as a model to test the catalytic activity of copper(II) complexes containing N,O-chelating Schiff base ligands. In this study, a series of copper(II) complexes containing respective Schiff base ligands, N′-salicylidene-2-aminophenol (1), N′-salicylidene-2-aminothiazole (2), and N,N′-bis(salicylidene)-o-phenylenediamine (3), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), UV-Visible (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopies. The results from the 4-nitrophenol reduction showed that 3 has the highest catalytic activities with 97.5% conversion, followed by 2 and 1 with 95.2% and 90.8% conversions, respectively. The optimization of the catalyst amount revealed that 1.0 mol% of the catalyst was the most optimized amount with the highest conversion compared to the other doses, 0.5 mol% and 1.5 mol%. Recyclability and reproducibility tests confirmed that all three complexes were active, efficient, and possess excellent reproducibility with consistent catalytic performances and could be used again without a major decrease in the catalytic activity

Causes of variation order in building and civil engineering projectsin Nigeria

Variation does not only affect labour productivity but also leads to the dispute, time and cost overrun. Consequently, it affects projects performance. It is, therefore, imperative for construction professionals to eliminate unnecessary additional cost from a project so as to optimize the client’s benefit against input resources. This paper identifies and examines the most significant causes that contribute to the variation orders. Also, Nigerian construction industry is used as a case study. Variation orders causing factors were assessed. Questionnaires were administered to clients, consultants and contractors to elicit information regarding variation causing factors. These factors were analyzed using frequency aggregation, mean score method and subsequently ranked according to their severity. The result revealed three most significant causes of variation which are: ‘Change of plan’’ with the highest frequency of 58% then followed by ‘‘Conflicting contract documents (50%). The next most frequent causing factors were the “substitution of materials” and “change in design” each with frequency of 43%. The least causing factor of variation was the “error and omission in design” with the frequency of 10%. Also differing site condition, new government regulation, weather condition were identified as other cause of variation with the frequency of 27%, 29% and 10% respectively. It has also shown that most critical source of variation order is the client due to change of plan then followed by consultant due to conflicting contract document