Communication in Physical Sciences

Crystal structure, in silico studies and anti-diabetic potentials of 3-e-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1h-pyrazol-4-yl)hyd -razinylidene]pentane-2,4-dione(hdpp)and its Cu(II) and Ni(II) complexes

Ndidiamaka Justina Agbo — 2024-10-17

The hydrazone, 3-E-[2-(1,5-Dimethyl-3-oxo-2-Phenyl-2,3-Dihydro-1h-Pyrazol-4-yl)Hydrazinylidene]Pentane-2,4-dione, HDPP was synthesized by coupling diazotized 4-aminoantipyrine with pentan-2,4-dione at < 5 ⁰C. The Cu(II) and Ni(II) complexes were prepared by refluxing stoichiometric amounts of metal salts and HDPP in ethanol for 6 h at 60 ⁰C. The ligand and complexes were characterized by UV-Vis, IR, NMR, and mass spectroscopies as well as by C, H, N, S elemental analysis, conductivity measurement, quantitative chloride determination and single crystal X-ray diffraction analysis. The compounds were screened in vitro for antibacterial activity against P. aeruginosa, S. aureus, Ecoli(Eco 6), E. coli(13), B. subtilis, S. pneumonia, P. mirabilis, S. intermedius and K. pneumoniae. The compounds were assayed for in silico molecular docking and in vivo anti-diabetic potentials. FTIR data showed shifts in ⱱ(C=O), ⱱ(N=H) and ⱱ(C=N) of the complexes implicating the involvement of these groups in complexation. Proton NMR shifts accounted for the methyl, phenyl and N-H protons of the ligand but indecipherable for the complexes due to paramagnetic effects. Conductivity values of HDPP and complexes showed the ligand and its complexes to be neutral. X-ray crystallographic data of HDPP show the ligand to have orthorhombic crystals with pbca unit cell a = 28.501(4) Å, α = 90°, b = 15.0494(19) Å, β = 90°; and c = 7.3234(9) Å, γ = 90° with Z=8. HDPP and its complexes exist in hydrazo form instead of azo form. It showed no activity against test organisms, but the complexes showed various degrees of sensitivities against the test bacterial strain at 10μg/cm³. Acute toxicity (LD₅₀) tests showed that HDPP and [Cu(HDPP)₂Cl₂] were non-toxic. In silico studies proved them to be drug candidates for diabetes with good oral bioavailability. In vivo, antidiabetic tests showed HDPP and [Cu(HDPP)₂Cl₂] to reduce the blood level of diabetic rats to within 61 to 67% better than the control drug glibenclamide within 14 days of treatment.

Analyzing market price equilibrium dynamics with differential equations: incorporating government intervention and market forces

Isaac Mashingil Mankili — 2024-10-17

This study seeks to investigate price stability in a dynamic market, where prices are subject to sudden impacts akin to those observed during the Covid-19 lockdown in 2020, as well as other influences introduced naturally or by price regulatory agencies. By examining functions derived from price observations, changes in prices, and changes in the rate of price changes, the study analyzes their stability amidst various influences. These influences are incorporated by examining factors affecting supply and demand quantities, which are modelled using a second-order linear differential equation; P′′(t)+a₁P′(t)+a₀P(t)=f(t). This study builds upon the research of Espinoza and Bob Foster, who analyzed a second-order differential equation with a constant inhomogeneity. It employs matrix methods to assess the stability of systems of differential equations. To analyze impulsive price changes modelled using the Dirac delta function and persistent price changes modelled with Heaviside's unit step function, the Laplace technique and its general inversion formula are applied. The study identifies conditions under which stability in the system can be maintained.

Statistical characterization of surface duct conditions and their implications on microwave propagation over Lagos, Nigeria

Olalekan Lawrence Ojo — 2024-10-17

Surface ducts, and atmospheric layers that trap and guide radio waves can significantly impact microwave signal propagation. Consequently, in this study, we analyzed their statistical occurrence in Lagos, Nigeria, using five years (2018-2022) of meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-5 reanalysis. The investigation focused on how factors like temperature, humidity, and pressure influence radio refractivity and the formation of surface ducts at different heights (100 m and 300 m) and observation times (00:00 and 12:00 hours). The results reveal a higher prevalence of surface ducts at 100 meters, particularly during the dry season (November-March) and at noon (12:00 hour). This implies that microwave signals are more likely to be trapped and travel farther during these periods, potentially causing interference with distant communication systems. Our findings establish the importance of considering surface ducts when designing and deploying communication infrastructure in coastal regions like Lagos.

Absorption studies of some agricultural solid wastes as biosorbent for the clean-up of oil spill

Henrietta Ijeoma Kelle — 2024-10-17

Oil spills are a major environmental threat, causing ecological, economic, and health issues. Traditional cleanup methods like chemical dispersants, in-situ burning, and synthetic sorbents have drawbacks such as secondary pollution and high costs. This study investigates the use of agricultural solid wastes—pineapple leaves, pineapple peels, and oil palm empty fruit bunch (OPEFB)—as biosorbents for oil spill cleanup. The biosorbents were evaluated for their oil sorption capacities under different temperatures and contact times. The oil sorption capacity for the milled samples at 25 °C showed that the standard synthetic sorbent had the highest capacity, reaching 14.08 g/g, while pineapple leaves had a peak capacity of 7.92 g/g at 3 minutes before stabilizing around 5.5 - 6.0 g/g. Pineapple peel and OPEFB exhibited lower capacities of 1.30 g/g and 2.66 g/g, respectively. At 30 °C, the standard sorbent again had the highest capacity at 14.73 g/g, with pineapple leaves reaching 8.13 g/g, OPEFB at 3.02 g/g, and pineapple peels at 1.96 g/g. The reusability and recovery efficiency of these materials were also assessed, with pineapple leaves showing high reusability (90 ± 0.01%) and recovery efficiency (90 ± 1.35%) at 25°C. The study demonstrates the potential of pineapple leaves as a viable biosorbent for oil spill remediation, given their relatively high and consistent oil sorption capacity and reusability. Pineapple peel and OPEFB, while less effective, could be considered for low-cost or supplementary adsorption materials. Further research is recommended to optimize these biosorbents and explore their practical applications in varying environmental conditions.

Computational study of the reaction mechanism for the formation of 4,5-diaminophthalonitrile from 4,5-dibromo-1,2-diaminobenzene and copper cyanide

Kayode Sanusi — 2024-10-17

This study investigates the mechanism of the reaction between 4,5-dibromo-1,2-diaminobenzene and copper cyanide using Density Functional Theory (DFT) calculations. The kinetics and the thermodynamic properties of the reaction were analyzed, revealing two major steps with activated complexes AC1 and AC2. Scheme 3 accurately depicts the reaction pathway. A triangular Cu-C=N moiety was found in the calculated transition states (TS), AC1 and AC2. The thermodynamic parameters for the first step show ΔG = -606.8 kJ mol^-1 , ΔH = -610.7 kJ mol^-1 and ΔS = -0.0132 kJ mol-1K^-1 while for the second step ΔG = -600.1 kJ mol^-1, ΔH = -603.6 kJ mol^-1, and ΔS = -0.0117 kJ mol-¹K^-1 were obtained. The activation energies (Ea and Ec) for steps 1 and 2 are 189.0 kJ mol^-1 and 210.6 kJ mol^-1, respectively. The positive values of ΔG# and ΔH#confirm the presence of energy barriers in both steps.These findings provide critical insights into the energetics and mechanism of the DDB reaction with copper cyanide, which is very crucial in understanding the strategy for the development of efficient synthetic procedures for the phthalonitrile.

Identification of Potential Aedes aegypti juvenile hormone inhibitors from methanol extract of leaves of Solanum erianthum: An in Silico approach

Taye Temitope Alawode — 2024-10-17

This study explores the potential of phytoconstituents from the methanol extract of Solanum erianthum leaves as inhibitors of juvenile hormones in Aedes aegypti using an in silico approach. Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified key compounds in the extract, including γ-sitosterol (40.25%), Ergost-5-en-3-ol (8.75%), and Stigmasterol (8.17%). Molecular docking simulations with the juvenile hormone-binding protein (PDB ID: 5V13) revealed that Ergost-5-en-3-ol (−8.316 kcal/mol) and 9,19-cycloergost-24(28)-en-3-ol (−8.388 kcal/mol) exhibited superior binding affinities compared to the standard juvenile hormone inhibitor Pyriproxyfen (−6.081 kcal/mol). Additionally, Phenol, 2,4-bis(1,1-dimethylethyl) (−7.063 kcal/mol) and DL-α-Tocopherol (−6.411 kcal/mol) showed moderate binding affinities. The physicochemical properties of these compounds, including their potential for intestinal absorption and blood-brain barrier penetration, were favourable. These findings suggest that the identified compounds may serve as promising bioinsecticides for controlling Aedes aegypti and mitigating the spread of vector-borne diseases.

Heavy metal status and health risks assessment of some local alcoholic and non-alcoholic beverages consumed in Aba, Nigeria

Emeka Chima Ogoko — 2024-10-17

The study was carried out to evaluate the levels heavy metals and health risk assessment in some local alcoholic (local gin, palm wine and herbal gin) and non-alcoholic beverages (zobo drink, kunu aya, and smoothies) consumed in Aba, Nigeria. Heavy metal concentrations were determined using atomic absorption spectrophotometer. The concentrations of Cr, Cd and Pb exceeded their respective standard maximum permissible limits. Computed hazard quotient was within safe limit (HQ<1) in all the studied samples, indicating that there were no potential non-carcinogenic health risks associated with consumption of these beverages with respect to Mn, Cr, Cd, Zn, Co, Cu, Fe and Pb. The incremental life cancer risk for Pb were within safe limit while the cancer risks of Cd in children exceeded the safe limit. The incremental life cancer risk for ingestion of Cr through alcoholic and non-alcoholic beverages were higher than the safe limit (<1.0 x 10^-4). The unacceptable high values of incremental life cancer risk for Cd and Cr demonstrated high prospect of potential life carcinogenic health risks in Nigerian child and adult population

Assessment of gaseous pollutants, particulate matter and meteorological parameters around Ibom Power Plant in Ikot Abasi Local Government Area of Akwa Ibom State, Nigeria

Akanimo Edet Jonah — 2024-10-17

This study investigates the concentrations of gaseous pollutants, particulate matter, and meteorological parameters around the Ibom Power Plant in Ikot Abasi Local Government Area, Akwa Ibom State, Nigeria, over one year. Using standard analytical methods, key pollutants such as NO₂, SO₂, CO, TVOC, CH₂O, PM₂.5, and PM₁₀ were monitored, alongside meteorological parameters like temperature, relative humidity, pressure, and wind speed. The monthly average concentrations of pollutants exceeded the Federal Environmental Protection Agency (FEPA) standards for NO₂, SO₂, CO, TVOC, CH₂O, PM₂.5, and PM₁₀. Seasonal analysis showed significant differences in pollutant levels between wet and dry seasons, with higher concentrations generally observed during the dry season. Notably, the Air Quality Index (AQI) indicated severe pollution levels for most pollutants throughout the study period, except for occasional moderate levels of SO₂ and CO. Correlation analysis revealed significant relationships between various pollutants, suggesting common sources or similar influencing factors. Geographic Information System (GIS) mapping further highlighted critical concentrations of NO₂ and CH₂O, with moderate levels of TVOC and low concentrations of SO₂, CO, PM₂.5, and PM₁₀. These findings underscore the potential health risks associated with prolonged exposure to elevated pollutant levels in the study area.

Pore parameters analysis of Echinochloa pyramidalis leaf dopped silver nanoparticles

Nyeneime William Akpanudo — 2024-10-17

Nanoparticles are significant products that have attracted a high level of market demand because of their outstanding surface properties. Silver nanoparticles are preferred in numerous industrial applications including water purification because of their thermal stability, particle size, surface area and other pore properties. In this study, silver nanoparticles (AgNPs) were synthesised using leaf extract of Echinochloa pyramidalis and later doped with the powder leaf sample. The products were analysed for their fundamental properties (i.e surface and pore properties) using nitrogen adsorption methods based on the BET models. The results, derived from Density Functional Theory (DFT) and differential pore volume (dV(d)) data, reveal that AgNPs exhibit a mesoporous structure with pore diameters ranging from 1.7656 to 2.7691 nm. The cumulative pore volume increases with pore width, reaching 5.52 × 10⁻² cm³/g, while the cumulative surface area grows to 47.1 m²/g, indicating a broad distribution of pore sizes. The differential analysis identifies key pore diameters at 2.3129, 2.4194, 2.5307, and 2.6472 nm as significant contributors to the material's pore volume and surface area. The average pore diameter is calculated to be approximately 4.69 nm. Langmuir and BET models for nitrogen adsorption provide surface area estimates of 522.586 m²/g and 167.780 m²/g, respectively, highlighting the high surface area to volume ratio of the nanoparticles. The findings confirm that the mesoporous nature of AgNPs, with a diverse range of pore sizes contribute to their significant surface area and adsorption capacity.

Development and applications of the Type II half-logistic exponentiated Inverse Weibull distribution

Yakubu Isa — 2024-10-17

A variety of distribution classes have emerged by expanding or generalizing well-known continuous distributions to enhance their flexibility and adaptability across various fields. One such distribution is the Inverse Weibull (IW) distribution, introduced by Keller and Kanath in 1982, which has proven effective in modelling failure characteristics. Over the years, several extensions of the IW distribution have been developed, including the Beta Inverse Weibull, Kumaraswamy-Inverse Weibull, and many others. This paper introduces a novel extension called the Type II Half-Logistic Inverse Weibull (TIIHLEtIW) distribution, derived from the Type II Half-Logistic Exponentiated-G (TIIHLEt-G) family proposed by Bello et al. in 2021. The TIIHLEtIW distribution incorporates two additional shape parameters, enhancing its flexibility. We provide the cumulative distribution function (cdf), probability density function (pdf), and key statistical properties, including moments, moment-generating function, reliability function, hazard function, and quantile function. Maximum likelihood estimation (MLE) is employed for parameter estimation, and a simulation study evaluates the performance of the MLEs. Finally, the applicability and superiority of the TIIHLEtIW distribution are demonstrated through a comparative study using two real datasets, showcasing its improved fit over several established distributions.

Stress concentration at a sharp corner of an elastic strip under anti-plane strain

Franca Amaka Nwafor — 2024-10-17

In this study, we investigated the behaviour of crack propagation and stress fields in power-law materials using finite element analysis. The study investigated how different power-law exponents influence stress intensity factors and crack growth. We observed from the results of the study significant variations in stress intensity factors with changes in the power-law exponent, which confirmed the critical role of material properties in predicting fracture behaviour. Materials with higher power-law exponents exhibited greater resistance to crack growth. These results promoted the necessity of considering material-specific properties, particularly the power-law exponent, in designing structural components to predict material performance and failure accurately. Based on the findings, it is recommended that engineers and material scientists prioritize the power-law behaviour of materials in structural design to improve fracture resistance. Future research should aim to develop more sophisticated models and incorporate a broader range of material behaviours and environmental conditions. Also, experimental validation and multi-scale analysis techniques should be employed to enhance the understanding of fracture behaviour in power-law materials. Establishing industry standards for assessing and reporting power-law behaviour will facilitate better application of research findings across various engineering disciplines.

Assessment of growth and adaptation rate of mung beans (Vigna radiata) planted in different planting periods in Abagana, SouthEastern Nigeria

Nnabike Francis Chukwura — 2024-10-17

Research was conducted to compare the growth characteristics, adaptation rate and attributes of mung beans (Vigna radiata) planted in different planting periods in Abagana, South Eastern Nigeria. The experiment was carried out at Bioresources Development Centre, Abagana, Anambra State, between February to April, May to July and August to October all in 2021. Mung beans seeds were planted using a planting distance of 30cm by 60cm in each planting period. The mung beans cultivated matured from nine to ten weeks after planting in each planting period and data was collected weekly in some phenotypic characteristics of the crop from the first week to the tenth week after planting. The highest mean values per plant of some agronomic characters collected from the field such as plant height (cm), number of leaves, length of leaves (cm), width of leaves (cm) and number of pods were 17.2cm, 18, 6.0cm, 4.8cm and 20 for those grown between February to April while those grown between May to July were 35.4cm, 39, 14.6cm, 12.9cm and 37, and those of August to October were 34.6cm, 37, 13.8cm, 13.0cm and 35.There were no significant difference (P>0.05) between the mung beans planted from May to July and those planted from August to October with respect to the above agronomic characters. Significant difference (P<0.05) existed between the mung beans planted from February to April when compared with those of May to July and August to October with respect to the above-mentioned agronomic characters. The result of the data collected from the field which was used as the plant adaptation parameters suggested that the mung beans grown between May to July and August to October had a better adaptation to the planting periods when compared with those grown from February to April 2021.

The geochemistry and petrogenesis of the iron-bearing sediments of Mfamosing, Southeastern (SE), Nigeria: Evidence from major oxides and its implication for industrial utilization

Benjamin Odey Omang — 2024-10-17

Iron ore, a critical resource for global industrial activities, plays a pivotal role in driving economic development and sustaining essential sectors such as construction, manufacturing, and infrastructure. Nigeria is endowed with substantial iron ore reserves, including the Mfamosing area, which has recently garnered attention for its untapped potential. However, limited comprehensive studies hinder a clear understanding of the iron ore occurrences and their industrial viability. This study addresses this gap by investigating the geochemistry of the iron-bearing metasediments in the Mfamosing area, utilizing X-ray fluorescence (XRF) to analyze major oxides. Field and laboratory studies were conducted, involving the collection of twenty-five (25) sediment samples from the Mfamosing area and subsequent XRF analysis. The results revealed a high content of Fe₂O₃ (hematite) in the range of 62.64–80.45 wt.%, indicating the dominance of iron-rich minerals. The presence of SiO₂, Al₂O₃, and other oxides suggests potential gangue minerals and aids in understanding the ore's composition. The petrogenesis study compares the geochemical characteristics of the Mfamosing iron ore with other iron-bearing formations globally. The findings indicate a sedimentary origin, with hydrothermal influence evidenced by Fe/Al and Fe/Si ratios. The low concentration of detrital materials further supports a primarily seawater-derived iron source. The iron ore has low concentrations of deleterious elements. Classification based on Fe₂O₃ content places most samples in the high-grade category, making them suitable as a primary raw material for steel production. Comparisons with other iron formations in Nigeria and worldwide affirm the Mfamosing iron ore's competitiveness on a global scale.

On the exponentiated Type II Generalized Topp-Leone-G Family of distribution: properties and applications

Ismail Adekunle Kolawole — 2024-10-17

In the modern era of statistics, distribution theory plays a crucial role in accurately modelling phenomena across various scientific fields. Traditional statistical distributions often fall short of adequately representing complex lifetime data. To address this limitation, this study introduces the Exponentiated Type II Generalized Topp-Leone-G (ET2GTL-G) family of distributions. This study employs the maximum likelihood estimation (MLE) method to estimate the parameters of the ET2GTL-G family and illustrates its application to two real-life datasets: (1) civil engineering hailing times, and (2) failure and service times for a windshield. Comparative analyses with existing distributions, such as the Kumaraswamy Extension Exponential (KEED), Kumaraswamy Exponential (KED), Exponential Generalized Exponentiated Exponential (EGEE), and Exponentiated Weibull-Exponential (EWED) distributions, highlight the superior goodness-of-fit and empirical flexibility of the ET2GTL-G distribution. For the first dataset, the ET2GTL-G distribution reported a minimum Akaike Information Criterion (AIC) value of 274.7174, compared to the next best-fit KED with an AIC value of 275.0377. For the second dataset, the ET2GTL-G distribution achieved an AIC value of 204.2458, outperforming the EGEE distribution which had an AIC value of 206.9956. These results underscore the potential of the ET2GTL-G family to improve the modelling of lifetime data, thereby contributing significantly to the fields of medicine, engineering, and beyond.

A multidisciplinary approach to historic building preservation

Efe Kelvin Jessa — 2024-10-17

Structural engineering in particular must work with other disciplines to accomplish the vital goal of preserving cultural heritage. The preservation of historic buildings guarantees that next generations will be able to experience and learn from these cultural objects, which serve as the physical embodiment of cultural identity and history. But structural problems frequently affect these structures, endangering their durability and structural integrity. While structural engineering is essential for identifying and resolving these problems, it cannot function alone. To create successful preservation plans that honor the structural and cultural characteristics of these structures, a multidisciplinary approach combining knowledge from material science, architecture, history, and conservation is required. Through a multidisciplinary perspective, this research investigates the function of structural engineering in the preservation of historic buildings. Through an analysis of case studies and existing practices, it draws attention to the advantages, difficulties, and potential paths forward of a cooperative approach to cultural asset conservation.

Thermal properties of diffusing species into some host metals

Nelson Nwagbogwu Akaezue — 2024-10-17

The study rigorously explored the thermodynamic properties of diffusing species by solving the spherical coordinate equation using the Frobenius method. This mathematical approach enabled the derivation of the partition function and energy equation, which were crucial in determining key thermal properties, including Helmholtz free energy, entropy, internal energy, and heat capacity. It was observed that internal energy and entropy exhibited a strong dependence on temperature, reflecting the dynamic nature of diffusing species in varying thermal environments. The findings provide valuable insights into the behavior of entropy within the classical domain, with both analytical expressions and graphical representations used to illustrate these thermal properties comprehensively. The graphical analysis highlighted the temperature-dependent trends and the critical points where classical and quantum mechanical effects influence the thermodynamic behavior of the system, offering a deeper understanding of the underlying physics.

Mechanical and morphological characterization of recycled low density polyethylene and polystyrene blends at varying compositions

Uche Ibeneme — 2024-10-17

This study investigates the mechanical and morphological properties of recycled low-density polyethylene (RLDPE) and recycled polystyrene (RPS) blends at varying compositions. Waste LDPE and PS were collected, processed, and compounded at ratios of 90/10, 70/30, 50/50, 30/70, and 10/90 using a two-roll mill. Tensile strength, tensile modulus, and impact strength were evaluated for each blend. The results shows that tensile strength increased from 8.5 Mpa for pure RLDPE to 12.2 Mpa at 50/50 bend, but decreased to 10.5 Mpa at higher RPS content. The tensile modulus showed a significant improvement from 140 Mpa in RLDPE to 380 Mpa in the 90/10 blend, reaching a peak of 650 Mpa in the 10/90 blend due to the rigidity of RPS. However, impact strength declined from 48 J/mm2 in the 10/90 blend, highlighting the brittleness introduced by higher RPS content. Scanning electron microscopy (SEM) revealed phase separation in all blends, with poor interfacial adhesion between RLDPE and RPS, Particularly at higher RPS compositions. This study underscores the potential for tailoring recycled polymer blends for specific applications, though further improvements are necessary to enhance interfacial compatibility and mechanical performance.

Extended goal programming DASH diet plan for stroke patients

Anayo Charles Iwuji — 2024-10-17

Goal Programming (GP) optimizes decisions in diet planning by computing efficient solutions that minimize deviations from the recommended nutrient goals target levels. Extended Goal Programming (EGP) enhances the flexibility of the GP model by using additional maximal deviation parameters that create a balance between efficiency and equity in the model. This work presents an EGP 2000-calorie daily Dietary Approaches to Stop Hypertension (DASH) diet plan for stroke patients. The proposed diet plan minimizes deviations from daily recommended nutrient targets, addressing the dual role of diet in stroke prevention and recovery. Data from the recommended food chart and nutrient levels were collected from the Nutritional Epidemiology Institute and DASH diet plan bulletins while the food samples and weights were obtained from Abia State, Nigeria. This study achieves three objectives: formulating an EGP diet model, presenting an efficient diet plan, and comparing results with those of other GP model variants. LINGO software is used in the analysis. The diet plan obtained showed six goals targets out of nine were achieved. A comparison of the EGP diet plan with the Chebyshev GP diet plan highlights the EGP’s flexibility and efficiency than the latter.

Derivation of a new Odd Exponential-Weibull distribution

Musa Ndamadu Farouq — 2024-10-17

The study of statistical distributions has led to the development of numerous extensions of well-known continuous distributions to enhance their flexibility and applicability across various fields. In this paper, we introduce a new three-parameter distribution known as the Odd Exponential-Weibull (OE-W) distribution, which extends the traditional Weibull distribution by incorporating additional parameter. We thoroughly investigate the mathematical properties of the OE-W distribution, deriving explicit formulas for the quantile function, moments, moment-generating function, survival function, hazard function, entropy, and order statistics. Parameter estimation is conducted using the maximum likelihood estimation (MLE) method, which is known for its robustness. To assess the reliability and accuracy of these parameter estimates, a Monte Carlo simulation study is performed. The simulation results indicate that the MLE method consistently yields reliable and accurate estimates for the parameters of the OE-W distribution. The introduction of this new distribution provides a valuable tool for modeling and analyzing data in fields such as reliability engineering and survival analysis, where flexible and accurate probability distributions are crucial.

The effects of external toxicants on competitive environment: a mathematical modeling approach

Samuel Sabastine Obonin — 2024-10-17

The presence of microplastics in aquatic environments has become a critical global problem. These tiny particles called microplastics less than 5mm in size pose severe risks to ecosystems and human health via the food chain due to the presence of heat and sunlight acting on these disposed plastics into streams and rivers, then flow into the seas and oceans in particular. Sources of microplastic pollution include the disposal of plastics into aquatic environments daily, the constant radiation of sunlight acting on larger disposed plastics leads to the frequent emission of micrometers of plastic into the aquatic environment. Once in aquatic systems, microplastics are ingested by marine life, entering the food chain and causing significant health hazards. Assessing the ecological risks of microplastics is essential, but few works have been done on the effects of microplastics as an external toxicant. This dissertation modified and analyzed a nonlinear mathematical model to study the effects of toxicant concentration leaks from external sources on competing species environments. The system's stability is examined using the tools of the theory of differential equations and computer simulations. The analysis results indicated a sharp increase in species one concentration from the initial value of 0.1 to a maximum of 23.7789 within a month with the toxicant influx atQ = 30 , after that decreasing to a stable minimum of 23.7786, for the rest of the months. It is further observed that the increased toxicant flux reduces the concentration of species one. The more toxicant influx increases, the more the effects are felt by species one and two and the resource biomass over the investigated time intervals.

Micromorphological and nutritional attributes of two varieties of Vernonia amagdalina del. domesticated in Delta State

Thelma Ewere Konyeme — 2024-10-17

This study examined the potential of two Vernonia amygdalina varieties (bitter and non-bitter) as sources of nutrients and medicinal compounds. Micromorphological analysis revealed variations in stomata size (bitter: 1.57±0.20 μm; non-bitter: 1.49±0.42 μm), index (bitter: 1.20±0.60%; non-bitter: 2.30±0.21%), and trichome index (bitter: 0.55±0.36%; non-bitter: 0.90±0.19%) between the varieties, while stomata type and anticlinal wall patterns were similar. Both varieties were rich in minerals, with bitter varieties containing higher levels of sodium (7.27±0.43 mg/g), potassium (17.07±0.45 mg/g), phosphorus (3.15±0.41 mg/g), iron (0.65±0.02 mg/g), zinc (0.15±0.03 mg/g), and copper (0.16±0.04 mg/g) compared to non-bitter varieties. Proximate composition analysis showed higher levels of crude fiber (1.76±0.50%), crude protein (21.07±0.30%), and carbohydrate (23.33±0.82%) in non-bitter varieties, while bitter varieties had higher levels of moisture (50.01±0.40%), crude ash (7.95±0.56%), and crude fat (2.15±0.20%). Phytochemical analysis revealed higher levels of tannin (0.13±0.85%), saponin (0.08±0.02%), and flavonoid (0.22±0.09%) in non-bitter varieties, while alkaloid levels (1.26±0.27%) were higher in bitter varieties. These findings suggest that both Vernonia amygdalina varieties are valuable sources of nutrients and phytochemicals, with potential applications in food and medicine.

Composition and distribution of polynuclear aromatic hydrocarbons contamination in surficial coastal sediments from Odidi Area of Delta State, Nigeria

Christopher Ejeomo — 2024-10-17

The distribution of PAHs in the environment has become widespread due to the impacts of human activities especially those relating to oil exploration and exploitation. This study was carried out to determine the composition and distribution of PAHs in sediments from Odidi River, Delta State, Nigeria. Samples were collected from two (2) upstream and downstream sampling points each at depths of 0 - 15cm from March 2015 to August 2016. Gas chromatography-mass spectrometry was used to determine the poly nuclei aromatic hydrocarbons (PAHs) concentrations in the samples. All data analyses were done using Microsoft Excel 2016. The results obtained showed that the mean concentrations of PAHs ranged from 4.37±1.29μg/g to 23.13±1.42μg/g (upstream), and from 2.22±1.11μg/g to 25.00±2.63μg/g (downstream). There was no significant difference between the values obtained upstream and downstream. Across the 18 months of the study, only Florene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo(a)anthracene and Crysene were detected in every month. The composition of PAHs shows a higher concentration of Heavy PAHs (HPAHs) with the mix of Light PAHs (LPAHs) indicating that they were released by both petrogenic and pyrogenic sources in the study area. The PAHs content of the sediments exceeds the threshold effect concentration (TEC) TEC and the threshold effect levels TEL limits PAHs in sediments indicating potential environmental and health threats.