Computing and Applied Sciences Impact

Isolation and characterisation of hydrocarbon-degrading microorganisms from soils contaminated with used engine oil

Thu, 05 Mar 2026 00:00:00 +0000

Soil contamination with used engine oil is a widespread environmental issue, posing risks to ecosystems and human health. The high levels of noxious compounds, such as trace elements and organic compounds that are composed of polycyclic aromatic rings (PAHs), immediately in used engine oil can disrupt various ecosystem reformations, like biogeochemical cycling, carbon sequestration, and the degradation of humus. Soil samples were collected from mechanic workshops where there are traces of hydrocarbons, and microorganisms were isolated using enrichment techniques with used engine oil as the sole carbon source, and the isolates were subjected to some biochemical tests. The results obtained revealed that the mean count of heterotrophic bacteria ranged from 2.0 x10⁸± 0.1 to 1.1 x 10⁸± 0.2 CFU/g while the mean count of hydrocarbon-utilising bacteria varied from 5.4 x 10⁷± 0.07 to 1.3 x 10⁷± 0.05 CFU/g, and the fungal populations ranged from 2.9 x 10⁷± 0.4 CFU/g to 1.0 x 10⁷± 0.1 CFU/g. A total of 12 hydrocarbon-degrading bacterial species and 16 filamentous fungi were isolated, characterized and identified. Some of the characterised isolates were Alcaligenes aquatilis > Pseudomonas sp. > Acinetobacter >Bacillus subtilis > Corynebacterium sp., and Flavobacterium sp. These oil-degrading organisms revealed hydrocarbon-degrading potential and bioremediation of the oil-contaminated sites.

Analytical and numerical study of the time-fractional Schrödinger equation for a free particle

Hassan Bukar — Mon, 01 Jun 2026 00:00:00 +0000

This study investigates the time-fractional Schrödinger equation (TFSE) for a free particle using the Caputo fractional derivative. The model extends the classical Schrödinger equation by incorporating memory effects through a non-integer order time derivative. By applying the Fourier transform method, an explicit solution is derived in terms of the Mittag–Leffler function, which generalizes the classical exponential evolution. The analysis reveals that the resulting dynamics are non-unitary, leading to a time-dependent total probability that deviates from the conservation property of standard quantum mechanics. Numerical illustrations demonstrate the influence of the fractional order ν on wave packet evolution and probability behavior. The results highlight the role of fractional calculus in modeling non-Markovian quantum systems and provide insight into the transition from fractional to classical dynamics as v→1.

An operator–theoretic analysis of the Adomian–Neumann series for the forced damped wave equation

Nwankwo Jude Chukwuyem , Rita N. Nwaka, James E. Kona — Thu, 04 Jun 2026 00:00:00 +0000

We establish an operator–theoretic framework for the Adomian–Neumann series applied to the forced damped wave equation with homogeneous Dirichlet boundary conditions in this paper. The second–order time derivative being inverted gives rise to a Volterra integral equation in time, by means of showing the Dirichlet Laplacian. Using this formulation, we demonstrate that the Adomian decomposition recursion is equivalent to the Neumann series expansion of the corresponding Volterra operator. As a result, the solution can be represented in terms of iterated time integrals and thus adopts a resolvent-type representation. In appropriate Sobolev spaces, we prove a convergence theorem, where factorial decay of successive terms arises naturally from repeated time integration. Furthermore, the resulting expansion is shown to reconstruct the Taylor series of the solution with respect to time. A Fourier mode example is presented to illustrate the analytical results.

Construction of semisymmetric entropic quasigroups

Pius Aje Onah — Sat, 20 Jun 2026 00:00:00 +0000

Elliptic curves are non-singular cubic plane-curves over a field containing at least one point and naturally form a group, where the associative property is based on Cayley-Bacharach theorem. A semisymmetric entropic (medial) quasigroup (SEQ) is a non-commutative generalization of this principle. This is a magma satisfying the pair of identities: and. Every SEQ is associated (not necessarily uniquely) with an Abelian group. In this paper, we give methods for constructing SEQs based on their corresponding Abelian groups. In particular, we show that SEQs are central quasigroups.