Titanium and its alloys are widely used in endoprostheses. The naturally formed titanium dioxide film on titanium surfaces improves chemical stability and enhances implant biocompatibility. However, oxidised titanium surfaces may also promote bacterial adhesion and biofilm formation, contributing to implant-associated infections. Therefore, surface modification represents a key strategy for controlling microbial-implant interactions. This article focuses widely used titanium alloy Ti-6Al-4V treated with a laser beam, which induces surface colour changes as a result of oxide formation. Laser processing enables controlled formation of micro- and nanoscale features, structural reconstructions, and defects that may influence the surface electrical charge and, consequently, cell immobilisation. Thus, the surface colour, electrical potential, and cell immobilisation capacity are likely interrelated. From a manufacturing perspective, titanium oxide colouring facilitates quality control and process reproducibility, as surface colour provides a rapid, non-destructive visual indicator of oxide thickness and treatment consistency. This study aims to identify correlations among surface colour, electrical potential, and cell immobilisation capacity on laser-treated titanium alloys. A relationship between the optical properties, electronic structure, and biological response of laser-processed titanium oxide films is established. Specifically, the blue colour saturation of the oxide film is inversely correlated with the electron work function. A more saturated blue corresponds to a lower work function, indicating a higher positive surface charge density. This shift is attributed to changes in electron affinity, likely resulting from laser-induced structural reconstruction and defect formation within the oxide layer. The proposed changes in electronic structure are supported by modifications in the electronic density of states, analysed using near-threshold photoelectron spectroscopy. The biological response is directly linked to these physical changes: enhanced immobilisation of yeast (Saccharomyces cerevisiae) cells on the treated alloy surface correlates with the electron work function. These results may assist in the development of controlled titanium oxide surfaces with enhanced biocompatibility.
In the face of today’s global and local challenges—such as environmental protection and combating climate change—these issues have become integral to economic policy. In this context, green financing gains special importance as a set of financial mechanisms aimed at promoting sustainable development and funding environmentally responsible projects. The objective of this research is to examine the role of green financing in the sustainable development process, evaluating its current application and future prospects in the Republic of Armenia. The study analyzes the main instruments of green financing (green loans, bonds, subsidies, and tax incentives), explores international experience, and reviews existing green financing initiatives and market characteristics in Armenia. Particular attention is paid to current challenges, including regulatory gaps, limited access to financial resources, and lack of professional expertise. The paper also emphasizes the role of financial technologies, public policy, and international cooperation in advancing green finance. Research findings indicate that while green financing in Armenia is still in its formative stage, it holds significant potential to become a stable and environmentally responsible driver of economic growth. The study concludes with a set of recommendations aimed at strengthening and effectively implementing green finance systems.
Entomofauna are essential for agricultural productivity and ecological balance. Understanding interactions among pollinators and pests is key to sustainable agriculture. Caterpillars, as pests, damage crops by feeding on tissues and spreading diseases, and reducing the yield and its quality. Therefore, early detection of caterpillars is essential for agriculture, it can be achieved using artificial intelligence embedded into agrobots or unmanned aerial vehicles following the concept of precision farming. This study introduces the dataset Caterpillar640, which contains 1,300 images of caterpillars, which were captured in natural conditions in Latvia. The images are annotated and prepared for artificial intelligence training by using YOLO architecture. The collected dataset is publicly available and distributed under an open license, providing valuable resources for research in precision farming and biodiversity monitoring. The artificial intelligence was developed using three convolution neural network architectures: YOLOv8, YOLOv9 and YOLOv10. The medium-sized models (YOLOv8m, YOLOv9m, and YOLOv10m) were selected for the comparison experiment. The comparison showed that YOLOv8m achieved the best results 0.887 mAP@0.50, YOLOv9m and YOLOv10m achieved 0.873 mAP@0.50 and 0.859 mAP@0.50, respectively. The experiment was conducted by repeating the training of each neural network model five times. The trained models can be embedded into IoT sensors, agrobots and drones for autonomous monitoring of fields, orchards and gardens offering an efficient solution for pest and biodiversity monitoring. Additionally, the dataset Caterpillar640 can be applied by researchers to train general convolutional neural networks for agricultural tasks combining it with other agricultural datasets that can impact on the accuracy of pre-trained models.
Oxidized titanium alloys, such as Ti 6Al 4V, are widely used in medical implants because their biocompatibility depends on surface properties like morphology, chemistry, and electrical charge. Laser processing in atmospheric, oxygenated conditions produces a thin oxide film with an embedded electrical charge, altering these surface characteristics. Although SEM is routinely employed to assess morphology and chemistry, its potential for evaluating surface charge is underexplored. In this study, we laser processed Ti 6Al 4V samples and used SEM in backscattered electron (BSE) mode to quantify surface charging. We correlated changes in BSE signal strength with work function measurements, finding that a work function increase from approximately 4.85 to 5.00 eV-indicative of greater surface charging-was accompanied by a measurable decrease in BSE image grey levels. Measurements at 10, 15, and 20 keV revealed a significant difference between 10 and 15 keV, while at 20 keV, the effect of surface charge on electron scattering was minimal. This approach demonstrates that BSE imaging can integrate charge analysis into routine SEM evaluations of laser-processed implant surfaces.
In the study of various spatial engineering problems (e.g. heat and mass transfer in multilayer media, diffusion and combustion processes), it is necessary to use 3-D partial differential equations (PDE), the solving of which is difficult. Therefore, in solving these problems, we apply the conservative averaging method. The conservative averaging method as an approximate analytical and numerical method for solving PDE or their systems with piece-wise constant (continuous) coefficients is under question. We consider averaging methods for solving the stationary 3-D boundary value problem of second order with piece-wise parameters in the 3-D domain for special source function. The hyperbolic-type splines, which interpolate middle integral values of a piece-wise smooth function, are considered. With the help of these splines, some boundary value problems of mathematical physics in 3-D with piece-wise coefficients are reduced to boundary value problems for ordinal differential equations in 1-D for one coordinate. The usage of this spline allows for diminishing the dimensions of the initial problem per one. The spline solution is used for different coordinates, in Cartesian coordinates, in cylindrical coordinates with axial symmetry and in spherical coordinates with axial symmetry. The analytical solution of the 1-D problem (boundary value problem for the ordinal differential equation) was compared with the corresponding spline function solution in the previously mentioned coordinates. Calculations to test theoretical assumptions and perform numerical experiments were proceeded with MATLAB.
