An analysis of common reinforcement methods of machine parts and theoretical bases for the selection of their chemical composition were carried out. Prospects for using flux-cored arc welding (FCAW) to restore and increase the wear resistance of machine parts in industries such as metallurgy, agricultural, wood processing, and oil industry were presented. It is noted that conventional series electrodes made of tungsten carbide are expensive, which limits their widespread use in some industries. The scope of this work includes the development of the chemical composition of tungsten-free hardfacing alloys based on the Fe-Mo-B-C system and hardfacing technology and the investigation of the microstructure and the mechanical properties of the developed hardfacing alloys. The composition of the hardfacing alloys was developed by extending the Fe-Mo-B-C system with Ti and Mn. The determination of wear resistance under abrasion and impact-abrasion wear test conditions and the hardness measurement by means of indentation and SEM analysis of the microstructures was completed. The results obtained show that the use of pure metal powders as starting components for electrodes based on the Fe-Mo-B-C system leads to the formation of a wear-resistant phase Fe(Mo,B)₂ during FCAW. The addition of Ti and Mn results in a significant increase in abrasion and impact-abrasion wear resistance by 1.2 and 1.3 times, respectively.

Fused deposition modeling (FDM) is one of the most accessible additive manufacturing (AM) technologies for processing polymeric materials. It allows processing most of thermoplastic polymers, with polyethylene terephthalate glycol-modified (PET-G) and polylactic acid (PLA). AM parts tend to display anisotropic behavior because of layer-by-layer fabrication and various technological parameters that can be set for 3D print, so it is hard to predict and analyze how the manufactured parts would behave under load. This research presents results of classic tensile strength tests performed on 57 PET-G specimens and 57 PLA specimens manufactured with varying technological parameters such as: printing temperature, print orientation, layer height, and infill percentage. Afterward, a comparative analysis is performed, proposing specific tensile strength (STS) as a benchmark to determine how 3D printed parts strength is varying due to beforementioned parameters, eliminating bias induced by varying weight of specimens. The biggest relative increase of UTS and the biggest relative decrease of STS was noted for variable infill percentage (increasing infill—PLA: 37.27% UTS increase and 30.41% STS decrease; PET-G: 24.42% UTS increase and 37.69% STS decrease). The biggest relative increase of STS between examined parameters was observed for both materials as the printing temperature was increased (27.53% for PLA and 12.69% for PET-G). Similar trends in STS changes were observed for both materials. Obtained data shows which FDM AM parameters are the most important to obtain the biggest UTS of manufactured parts, and those do not overlap with parameters needed to obtain optimal strength-to-weight ratio.

Whey is a byproduct of dairy production that possesses high nutritional value and versatile applications across various industries. In the framework of circular economy, the reutilization of whey is essential to transform this high-volume byproduct into a valuable resource. In this narrative review, the authors focus on trends in the utilization of whey for manufacturing functional and nutritional beverages. This publication summarizes the current information on whey composition based on various influencing factors and explores the technological processes currently used in whey-based beverage production and analysis, as well as nutritional profiles and properties of whey-based drinks with functional modifiers. Information about whey processing methods, compositional profiles, and whey-based beverages’ health benefits along with the author-proposed typology of functional drinks are summarized in tables throughout the paper.

The design and manufacturing technology of interference-absorbing short-wave filters based on a layered composition of Si–SiO on a sapphire substrate of various shapes was developed. A transition layer of SiO was applied to the surface of the substrate, alternating with layers of Si–SiO with an odd number of quarter-wave layers of materials with high (Si) and low refractive indices (SiO), and the application of an outer layer of SiO as an appropriate control of the materials’ thickness. The optical properties of the infrared light filter were studied. It was established that the created design of the light filter provides the minimum light transmission in the visible region of the spectrum from 0.38 to 0.78 µm and the maximum in the near infrared region from 1.25 to 5 µm and has stable optical indicators. A method for studying the stress–strain state and strength of a multilayer coating of a light filter under the action of a local arbitrarily oriented load was developed. For simplicity in the analysis and for obtaining results in the analytical form, the one-dimensional model of the configuration “multilayer covering—firm substrate” constructed earlier by authors was used. From a mechanical point of view, the upper protective layer of the multilayer coating was modeled by a flexible plate, and the inner operational composite N-layer was subjected to Winkler’s hypothesis about the proportionality of stresses and elastic displacements.

This paper describes the combined detection of coating and rust damages on painted metal structures through the multiclass image segmentation technique. Our prior works were focused solely on the localization of rust damages and rust segmentation under different ambient conditions (different lighting conditions, presence of shadows, low background/object color contrast). This paper method proposes three types of damages: coating crack, coating flaking, and rust damage. Background, paint flaking, and rust damage are objects that can be separated in RGB color-space alone. For their preliminary classification SVM is used. As for paint cracks, color features are insufficient for separating it from other defect types as they overlap with the other three classes in RGB color space. For preliminary paint crack segmentation we use the valley detection approach, which analyses the shape of defects. A multiclass level-set approach with a developed penalty term is used as a framework for the advanced final damage segmentation stage. Model training and accuracy assessment are fulfilled on the created dataset, which contains input images of corresponding defects with respective ground truth data provided by the expert. A quantitative analysis of the accuracy of the proposed approach is provided. The efficiency of the approach is demonstrated on authentic images of coated surfaces.

The present work reports the results of a systematic study on the evolution of the morphological properties of porous carbons derived from coffee waste using a one-pot potassium-hydroxide-assisted process at temperatures in the range of 400–900 °C. Raw materials and obtained carbons were studied by TG, DTG, SEM and nitrogen adsorption porosimetry. The decomposition temperature ranges for hemicellulose, cellulose and lignin as the main component of the feedstock have been established. It is shown that the proposed method for the thermochemical treatment of coffee waste makes it possible to obtain activated carbon with a controllable pore size distribution and a high specific surface area (up to 1050 m²/g). A comparative study of the evolution of the distribution of pore size, pore area and pore volume has been carried out based on the BJH and NL-DFT (slit-like pores approximation) methods. The fractal dimension of the obtained carbons has been calculated by Frenkel–Halsey–Hill method for single-layer and multilayer adsorptions.