Central Asian Journal of Theoretical and Applied Science

Assessing Industrial Pollution in the Tigris River Using Antibiotic-Resistant Pseudomonas spp. as an Environmental Indicator

Yonis Ahmed Kitan — 2026-02-11

Industrially emitted effluents have been recognized to be one of the major sources for environmental pollution, releasing chemicals, nutrients, and traces of antibiotics into water bodies. In this regard, this study examined the role of industrial pollution in antibiotic resistance among Pseudomonas spp. isolated from surface water in the Tigris River, specifically in Baghdad’s industrial area. A total of 80 water samples were obtained for a period of one year from four locations (S1-S4), which were selected based on variations in levels of pollution caused by industries, as well as agricultural activities. Phenotypic analysis was employed for identifying, characterizing, and differentiating isolated Pseudomonas spp. Sensitivity tests performed among antibiotics have shown resistance rates to be high for Piperacillin (78%), Ceftazidime (65%), Ciprofloxacin (60%), and Tetracycline antibiotics (55%), but low for Imipenem (21%). A resistance rate of 93.75% for combinations involving two or more antibiotics, as well as 52% for six or more antibiotics, has been observed. Additionally, Multiple Antibiotic Resistance Index (MARI) has been observed to exceed 0.2 for all locations, with S2 having the highest MARI value (0.51), which is an area where industries release their highest amounts of waste. Correlation analysis has shown a positive relationship for all locations between MARI values, Total Nitrogen (TN), Total Phosphorus (TP), Total Suspended Solids (TSS), Turbidity (TUR), Turbidity (TUR), but an inverse relationship for pH. Phylogenetic analysis has provided evidence for resistance levels among isolated groups A and B1 in highly polluted areas. In conclusion, selective pressures caused by industries, as well as agricultural activities, have increased MDR levels among environmental isolates. Heat map analysis, along with plot analysis, has provided evidence for a positive relationship between levels of environmental pollution and antibiotic resistance. These observations have clearly provided evidence that Pseudomonas spp. can be considered an ideal bioindicator for industrial pollution, emphasizing an immediate need for efficient approaches for managing industrial water waste, which could otherwise pose serious threats to environmental, as well as human, health due to increased levels of MDR bacteria.

A High-Order Finite Element Framework for Solving Nonlinear Schrodinger Equations in Complex Domains

Qasim Abd Ali Tayyeh — 2026-02-11

This paper introduces a new type of high order finite element method for numerically solving NLSEs in complex domains. NLSEs play a central role in the modelling of wave phenomena in optics, quantum mechanics, and fluid dynamics, however, finding their solution in geometrically complex domains is still a challenge due to nonlinearities and boundary complexities. The framework that is proposed is basing on high-order finite element discretization on unstructured meshes, which makes it possible to appropriately and flexibly compute with complex geometries. Key aspects are weak formulation with adaptation time integration, strong treatment of terms with nonlinearity by Newton-type iterations, and assignment of various other boundary conditions. Numerical experiments show high order convergence rates, conservation properties and better performance than low order methods. In order to validate the efficiency and accuracy of the framework, the soliton propagation, vortex dynamics and domains with irregular shapes are used as the benchmarks. This work leads to the development of numerical methods for NLSEs uncombining geometric flexibility and high accuracy which may provide a means for simulation in photonic devices, Bose-Einstein condensates, and other applications.

The Importance and Practice of International Financing in The Forestry Sector

Mamatqulova Muxlisa Mamirjanovna — 2026-02-14

This article analyzes the role, importance and practical mechanisms of international financing in the forestry sector of Uzbekistan. Major projects implemented by international institutions such as the World Bank, ADB, EBRD, GEF, GCF and UNDP during 2021–2024, their financial volume, target areas and territorial coverage are highlighted. The results of the study demonstrate the effectiveness of international financial resources in restoring forest ecosystems, combating soil degradation, preserving biodiversity, adapting to climate change and providing employment to the local population. The article also presents institutional, technical and strategic proposals for developing cooperation with international financial institutions, including the Forest Investment Pipeline, donor coordination mechanisms and a multi-source financing model. The study substantiates the strategic importance of international financing in the sustainable development of forestry.

Experimental Validation of Earth Abundant Heterogeneous Catalysts Toward Sustainable Energy Conversion

Shipon Chandra Barman — 2026-02-20

Background: The clean energy sector needs hydrogen as its main energy carrier but
biomass-based hydrogen production faces obstacles because tar forms which damages catalysts
while decreasing system efficiency. The high catalytic activity of noble metal catalysts does not make
them suitable for industrial operations because of their expensive price and their tendency to form
coke deposits. Methods: Multiple heterogeneous catalysts, including Ni/Al₂O₃ and Ni/MgO and Fe
based and dolomite and alkali-promoted and noble metal catalysts, were tested experimentally in
this research. The fixed-bed reactor served as the experimental setup for hydrogen production and
tar cracking tests, which operated at elevated temperature levels. Gas chromatography was used to
measure hydrogen production and H₂/CO ratio and tar removal efficiency and carbon deposition
while conducting three separate experiments to prove their findings. Results: Noble metal catalysts
the maximum hydrogen at 64.5 vol.%, and Ni/Al₂O₃ followed with a 61.8 vol.% hydrogen yield are
produced. The tar removal process reached its peak efficiency with dolomite, which removed 93.8%
of tar while achieving minimal carbon buildup. The alkali-promoted catalysts showed the ability to
prevent coke development. Hydrogen production efficiency needed to be reduced when tar
cracking performance reached its highest level for every catalyst system. Conclusion: This study
shows that catalysts made from earth-abundant elements provide budget-friendly solutions that
match noble metal performance in durability. Sustainable hydrogen production systems require
combined or dual-catalyst approaches to attain their compulsory hydrogen yield and tar removal
and preserve functioning stability for protracted periodsle.

Thickness-Dependent Optical Confinement in Glass/TiO₂/Perovskite (MAPbI₃) Thin Films: A Spectral Integration Approach

Abdullah Mohaned Lateef — 2026-02-23

In this study, we proposed a theoretical investigation of the optical interaction of
multilayer thin films designed from glass/TiO2/MAPbI₃ using the Transfer Matrix Method (TMM)
in the range of 300–800 nm of visible light. The effect of TiO2 interlayer thickness (20 nm, 50 nm,
and 100 nm) on the confinement of interference light within a 400 nm-thick MAPbI₃ absorber layer
was analyzed. Our results showed that adding a layer of TiO₂ modifies the phase conditions within
the structure, leading to a redistribution of the optical field and a thickness-dependent absorption
behavior. We also used spectral integration to determine the overall effective absorption across the
visible light spectrum. We studied three layer thicknesses, but the 50 nm TiO₂ layer exhibited the
highest average absorption (0.259), representing an improvement of approximately 5.3% compared
to the 100 nm thickness. In the results obtained, we focused on the importance of improving the
thickness of the multiple layers in perovskite systems that are designed as a crystalline structure,
and cover important applications that work on developing the structure of thin-film photovoltaic
structures.