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Orthoses are commonly used for treating injuries to improve the quality of life of patients, with customized orthoses offering significant benefits. Additive manufacturing, especially fused deposition modelling, enhances these benefits by providing faster, more precise, and more comfortable orthoses. The present study evaluates nine polymeric materials printed in horizontal and vertical directions by assessing their performance through compressive, flexural, and tensile tests. Among all materials, polycarbonate, polylactic acid, and ULTEMTM 1010 showed the most promising results, not only because they had the highest mechanical values, but also due to their minimal or no difference in performance between printing directions, making them advantageous in orthoses fabrication. Based on this, a finite element model of an ankle–foot orthosis was developed to simulate the deformation, strain, and stress fields under static conditions. The findings aim to optimize material selection for orthotic fabrication, where ULTEMTM 1010 is presented as the material with improved performance and durability. [ABSTRACT FROM AUTHOR]

The growing use of plastics has simultaneously increased the accumulation of ubiquitous plastic waste in landfills and the environment, posing global aesthetic and ecological challenges. Consequently, various waste disposal procedures are implemented, with recycling or waste recovery occupying a prominent position in the waste management hierarchy. Plastic waste recovery includes mechanical, chemical, or energy-related processes, yielding products suitable for reuse. This method of plastic waste disposal is currently the most cost-effective solution, aiming to avoid landfill dumping and reduce waste volumes. In the past two decades, the focus of waste management has shifted increasingly from disposal methods to prevention and recycling, with European Union (EU) member states committed to implementing and harmonising current legal measures related to plastic items prescribed by EU directives. The ultimate goal is to transition toward a circular economy model, promoting the sustainable use of plastics and minimising waste generation. Despite the increasing waste production rate in the EU, the quantity of municipal waste dumped in landfills has decreased overall, partly due to the introduction of European legislation, such as the Directive 62/1994 on packaging and packaging waste. However, Croatia’s plastic packaging waste recycling rate still lags behind the EU average. [ABSTRACT FROM AUTHOR]

Rheological behaviors of polymeric materials have been observed to be temperature-dependent, which demands considering temperature effects in constitutive models. In this article, a fractional rheological model is developed to describe creep and relaxation behaviors, of which linear criterion between model parameter and temperature is established. Temperature-dependent fractional orders of the model are naturally interpreted by the well-known master curve. Numerous experimental data in a limited range of temperatures are employed to certificate the applicability of the proposed models. Simulation results demonstrate that the models are equipped with a simpler formulation and high fitting accuracy compared with existing models. [ABSTRACT FROM AUTHOR]

Microbial corrosion of waterproof coatings causes structural damage to buildings and renovation materials and severely threatens human health. In practical applications, coatings with different base materials show different durabilities to external environmental influences. There is little literature on the antimicrobial durability performance of waterproof coatings. Therefore, this paper selected four standard waterproofing coatings, including polyurethane coatings, cement-based coatings, asphalt-modified polymer coatings, and polymer emulsion coatings, as the main body of this study. Their antimicrobial abilities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, Candida albicans, and mold were tested after experiencing three kinds of harsh environments: Ultraviolet ray (UV), water immersion, and low temperature. The results show that the extreme climates significantly reduced the ability of the four coatings to resist mold, and the highest growth rate of bacteria was 54.64%. Under UV conditions, the polymer emulsion coatings were significantly more resistant to Candida albicans, and the optical density of the bacterial liquid showed a negative growth trend. The microstructural integrity of the polymer emulsion coatings was found to be damaged by Scanning Electron Microscope (SEM) observation. This work improves the durability application research on these coatings and provides a valuable reference for developing new environmentally friendly, antibacterial, and anticorrosive waterproof coatings. [ABSTRACT FROM AUTHOR]

The growing use of plastics has simultaneously increased the accumulation of ubiquitous plastic waste in landfills and the environment, posing global aesthetic and ecological challenges. Consequently, various waste disposal procedures are implemented, with recycling or waste recovery occupying a prominent position in the waste management hierarchy. Plastic waste recovery includes mechanical, chemical, or energy-related processes, yielding products suitable for reuse. This method of plastic waste disposal is currently the most cost-effective solution, aiming to avoid landfill dumping and reduce waste volumes. In the past two decades, the focus of waste management has shifted increasingly from disposal methods to prevention and recycling, with European Union (EU) member states committed to implementing and harmonising current legal measures related to plastic items prescribed by EU directives. The ultimate goal is to transition toward a circular economy model, promoting the sustainable use of plastics and minimising waste generation. Despite the increasing waste production rate in the EU, the quantity of municipal waste dumped in landfills has decreased overall, partly due to the introduction of European legislation, such as the Directive 62/1994 on packaging and packaging waste. However, Croatia’s plastic packaging waste recycling rate still lags behind the EU average.

Microbial corrosion of waterproof coatings causes structural damage to buildings and renovation materials and severely threatens human health. In practical applications, coatings with different base materials show different durabilities to external environmental influences. There is little literature on the antimicrobial durability performance of waterproof coatings. Therefore, this paper selected four standard waterproofing coatings, including polyurethane coatings, cement-based coatings, asphalt-modified polymer coatings, and polymer emulsion coatings, as the main body of this study. Their antimicrobial abilities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus, Candida albicans, and mold were tested after experiencing three kinds of harsh environments: Ultraviolet ray (UV), water immersion, and low temperature. The results show that the extreme climates significantly reduced the ability of the four coatings to resist mold, and the highest growth rate of bacteria was 54.64%. Under UV conditions, the polymer emulsion coatings were significantly more resistant to Candida albicans, and the optical density of the bacterial liquid showed a negative growth trend. The microstructural integrity of the polymer emulsion coatings was found to be damaged by Scanning Electron Microscope (SEM) observation. This work improves the durability application research on these coatings and provides a valuable reference for developing new environmentally friendly, antibacterial, and anticorrosive waterproof coatings.

Soft actuators are one of the most promising technological advancements with potential solutions to diverse fields’ day‐to‐day challenges. Soft actuators derived from hydrogel materials possess unique features such as flexibility, responsiveness to stimuli, and intricate deformations, making them ideal for soft robotics, artificial muscles, and biomedical applications. This review provides an overview of material composition and design techniques for hydrogel actuators, exploring 3D printing, photopolymerization, cross‐linking, and microfabrication methods for improved actuation. It examines applications of hydrogel actuators in biomedical, soft robotics, bioinspired systems, microfluidics, lab‐on‐a‐chip devices, and environmental, and energy systems. Finally, it discusses challenges, opportunities, advancements, and regulatory aspects related to hydrogel actuators. [ABSTRACT FROM AUTHOR]

Copyright of Annual of the General Union of Arab Archaeologists Studies on the Arab World Antiquities is the property of General Union of Arab Archaeologists and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of sustainable flame retardants is gaining momentum due to their enhanced safety attributes and environmental compatibility. One effective strategy is to use waste materials as a primary source of chemical components, which can help mitigate environmental issues associated with traditional flame retardants. This paper reviews recent research in flame retardancy for waste flame retardants, categorizing them based on waste types like industrial, food, and plant waste. The paper focuses on recent advancements in this area, focusing on their impact on the thermal stability, flame retardancy, smoke suppression, and mechanical properties of polymeric materials. The study also provides a summary of functionalization methodologies used and key factors involved in modifying polymer systems. Finally, their major challenges and prospects for the future are identified. [ABSTRACT FROM AUTHOR]

Under high power UV irradiation, radicals can be generated from double bonds through photodissociation, H‐abstraction, or oxygen initiation mechanisms. This eliminates the need for externally added initiators in photopolymerization. This study investigates high‐power sunlight‐simulated UV‐induced free radical polymerization under various experimental conditions, including the presence of inhibitors, open or closed systems, and partial degassing. Additionally, high‐power sunlight‐simulated UV‐induced atom transfer radical polymerization is explored by externally adding CuBr2/ligand (1:2) catalyst at 100 or 1000 ppm molar concentration of copper. Delicate fabrication of real‐world thin films, coatings, and delicate 3D composites further demonstrates the high reliability and versatility of this technology. [ABSTRACT FROM AUTHOR]

Recent advancements in polymer science and manufacturing technologies triggered new developments of porous materials used for mitigating heat losses, such as thermal insulating polymeric foams. The major bottleneck in the optimization of these products, however, remains the absence of analytical methods able to scrutinize their large design space reasonably quickly and cost-effectively. This manuscript targets the paucity of data for polymeric foams by illustrating, at a proof-of-principle level, that several well-established analytical methods including optical microscopy, pycnometry, dielectric spectroscopy, thermogravimetric analysis, and nuclear magnetic resonance can be exploited for an extensive, yet logistically efficient, characterization of these materials. The purpose of this study is thus introducing an experimental platform for the characterization of market foam products and for the development of new polymeric foams with pore sizes that are particularly relevant for industrial and residential thermal insulation. Since this work introduces several new methodologies, it may be used as a guide for both laboratory users and specialists in the field, who may further improve the herein proposed experimental concepts.

This document is an editorial published in the journal Frontiers in Materials. It discusses the ongoing research in flexible polymeric materials with controlled nanostructures and their potential applications in various fields. The editorial emphasizes the importance of understanding the structure-property correlations in designing materials with enhanced mechanical, electrical, thermal, and optical properties. The document also highlights recent advancements in the synthesis and assembly techniques of these materials and their integration into practical devices. The editorial aims to provide a comprehensive overview of recent advancements in this field and inspire future research and innovation. [Extracted from the article]

The work examines the characteristics of the static and kinetic friction of five types of polymer materials and composites obtained by 3D printing, which are united into 2 groups: group A: PLA, Tough PLA (Technical Polylactic acid), and SteelFill (PLA with stainless steel powder approx. w80%15) and group B: PETG (Polyethylene terephthalate): PETG and CarbonFilTM (PETG with carbon fibers). Results were obtained and analyzed for the variation of the static and kinetic friction force, the static and kinetic coefficient of friction (COF), and the difference between the static and kinetic COF (a jump in COF, known as Stick-slip) from the magnitude of the normal load in two cases of contact with a steel counter-body - without lubricant and with SAE15W40 oil.

Polymer materials and their composites are one of the most frequently used materials in the packaging and food industries. This applies to both disposable and reusable packaging, layered films with barrier properties, as well as densely overprinted polymer films and metallized food wrap films. According to statistical data from Plastics Europe, approximately 40% of processed thermoplastics are used to produce packaging, including single- and multi-layer film packaging. Growing requirements and new EU directives require the use of recycled materials in new products, which is not easy because the properties of recyclates may differ significantly from those of the primary materials with which the former are mixed. This work attempts to analyze the properties of the primary material used to produce a film using the casting method in comparison with the industrial recyclate obtained by the processing of film made of the primary material and then overprinted and metallized. The process of obtaining re-granulates and preparing test samples was presented, and the mechanical, structural, and thermal properties of the tested materials were compared. The conducted research and the obtained results demonstrated the advisability of conducting advanced mechanical recycling, which leads to obtaining re-granulates with repeatable processing properties and thermal and mechanical properties comparable to the original material despite the impurities they contain. [ABSTRACT FROM AUTHOR]

The continuous growth of additive manufacturing in worldwide industrial and research fields is driven by its main feature which allows the customization of items according to the customers' requirements and limitations. There is an expanding competitiveness in the product development sector as well as applicative research that serves special-use domains. Besides the direct use of additive manufacturing in the production of final products, 3D printing is a viable solution that can help manufacturers and researchers produce their support tooling devices (such as molds and dies) more efficiently, in terms of design complexity and flexibility, timeframe, costs, and material consumption reduction as well as functionality and quality enhancements. The compatibility of the features of 3D printing of molds with the requirements of low-volume production and individual-use customized items development makes this class of techniques extremely attractive to a multitude of areas. This review paper presents a synthesis of the use of 3D-printed polymeric molds in the main applications where molds exhibit a major role, from industrially oriented ones (injection, casting, thermoforming, vacuum forming, composite fabrication) to research or single-use oriented ones (tissue engineering, biomedicine, soft lithography), with an emphasis on the benefits of using 3D-printed polymeric molds, compared to traditional tooling. [ABSTRACT FROM AUTHOR]

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones—from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann–Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique. [ABSTRACT FROM AUTHOR]

The proliferation of polymer science and technology in recent decades has been remarkable, with synthetic polymers derived predominantly from petroleum-based sources dominating the market. However, concerns about their environmental impacts and the finite nature of fossil resources have sparked interest in sustainable alternatives. Bio-based polymers, derived from renewable sources such as plants and microbes, offer promise in addressing these challenges. This review provides an overview of bio-based polymers, discussing their production methods, properties, and potential applications. Specifically, it explores prominent examples including polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polyhydroxy polyamides (PHPAs). Despite their current limited market share, the growing awareness of environmental issues and advancements in technology are driving increased demand for bio-based polymers, positioning them as essential components in the transition towards a more sustainable future. [ABSTRACT FROM AUTHOR]

The development of new polymer materials is an emerging field for more than 100 years. However, it is currently facing major challenges and the application of digital methods can help to develop new processes, discover new materials and, thus, contribute to the challenges of today and the future. Though, the application of digital methods in the field of polymer science is currently very limited, when compared to other classes of materials such as small molecules or inorganic high‐performance materials. Nevertheless, there are already first, very promising approaches. The current review article focuses on the application of these methods in different aspects of polymer research including polymer design, synthesis, and characterization. Furthermore, the digital discovery of polymer engineering is highlighted in detail showing the broad range of potential applications of these methods in polymer science. Finally, future possibilities and opportunities are derived from the current state‐of‐the‐art and perspectives for a potential evolution of polymer science are provided. [ABSTRACT FROM AUTHOR]

The investigation revealed patterns in the formation and localization of deposits of polishing powder wear nanoparticles on the processed surface during the polishing of polymeric materials using disperse systems of micro- and nanopowders. The total scattering cross section of polishing powder wear nanoparticles on sludge nanoparticles increases nonlinearly with the movement of particles, extremally depends on the product of spectral separation for dielectric constant separation between the processed material, polishing powder, and the disperse system, and exponentially increases with the resonator detuning. When polystyrene is polished using cerium dioxide micropowder, deposition on the processed surface is most likely to occur, with the maximum value of the total scattering cross section of polishing powder wear nanoparticles on sludge nanoparticles being at 49.7 Mb. Experimental data indicate that the localization of deposits with polishing powder wear nanoparticles on the processed surface occurs according to the distribution function of the total scattering cross section of polishing powder wear nanoparticles on sludge nanoparticles across circular zones, which aligns well with experimental results, within 12.5%. The experimentally determined average thickness of the deposit fragments of polishing powder wear nanoparticles, forming complete or partial coverage of the component surface, ranges from 1.1 to 1.5 µm. [ABSTRACT FROM AUTHOR]

The objective of this research is to evaluate various polymeric materials that have the potential to serve as substitutes or supplements to heavy vehicle structures for radiation-intensive environments. The materials under investigation include Nylon 6 (PA-6, C6H11NO), polyethylene (PE, C2H4), polypropylene (PP, C3H6), polyvinyl chloride (PVC, C2H3Cl), and polymethylacrylate (PMMA, C5H8O2). This study's primary aim is to determine each material's effectiveness in shielding against radiation and reducing exposure to vehicle occupants. As a new approach, this research examines the impact of utilizing polymeric materials and the potential health hazards for young drivers of both sexes, such as developing solid cancers from radiation exposure. According to the study, PVC was the most efficient polymer with a Transmission Factor (TF) of 0.44, leading to a 56% decrease in the relative risk estimate for the maximum thickness evaluated (20 cm). On the other hand, PP was identified as the least efficient, with a TF of 0.65, resulting in a 35% reduction in the relative risk estimate for the same thickness. The study concludes that each polymer has varying degrees of attenuation and that combining their properties is essential to achieving the desired level of risk reduction.

Abstract Under high power UV irradiation, radicals can be generated from double bonds through photodissociation, H‐abstraction, or oxygen initiation mechanisms. This eliminates the need for externally added initiators in photopolymerization. This study investigates high‐power sunlight‐simulated UV‐induced free radical polymerization under various experimental conditions, including the presence of inhibitors, open or closed systems, and partial degassing. Additionally, high‐power sunlight‐simulated UV‐induced atom transfer radical polymerization is explored by externally adding CuBr2/ligand (1:2) catalyst at 100 or 1000 ppm molar concentration of copper. Delicate fabrication of real‐world thin films, coatings, and delicate 3D composites further demonstrates the high reliability and versatility of this technology.

Nails are involved in most everyday activities, whether physically for seemingly simple actions such, protection against external factors or roles with an aesthetic implication, for the integration of people into society. Often, any change at an aesthetic level is felt both from the point of view of the patient, who can be affected at a psychological level, feeling anxiety due to the lack of a part considered essential, and from the point of view of society that imposes a certain standard to be accepted in the community. Because of this societal standard, people with an untreatable nail deformity or disease can feel marginalized and excluded. Recently, an important number of studies have been carried out in this field, especially since the uses of polymeric materials have gained a wide field of applicability. In this work, the comparison between three types of polymeric materials used in salon work was highlighted, for the aesthetic treatment of some diseases with a long healing time or even untreatable, by making prostheses for the affected nail plates of onycholysis. The mentioned materials were analysed microscopically, tested for roughness and hardness, and tested for compression and bending resistance, in order to understand how a nail prosthesis made of these materials behaves under different actions and external factors to which the nails are subjected to in daily activities. Finally, the method of making a nail prosthesis from one of the tested polymeric materials was presented and the importance of the functions of the nails, both aesthetic and medical, was highlighted.

This work synthesized a thermoplastic polymer with varying densities along one direction using additive manufacturing technology to study the dynamic and static characteristics of functionally graded viscoelastic materials (FGVMs). To describe the mechanical properties of FGVMs, an analytical formulation based on the sigmoid-law formulation was proposed. The experimental program is conducted on 3D-printed samples, and various tests are conducted to examine the performance of such materials. Furthermore, the finite element method was used to evaluate the structural system's flexural properties. The influences of FG parameters and geometrical properties on flexural and reverse bending fatigue life are analyzed. The results show that increasing porosity from 10% to 30% at a power-law index (k = 2) reduces bending strength by 31.25 percent and deflection by around 11.2 percent for VE samples. Changing the power-law exponent from 0.5 to 10 increases fatigue strength by 35 %.

Modern industries, including those in construction, increasingly uses various types of polymer materials, which should be characterized by good mechanical properties. In this work, the effect of strain rate (10, 20, and 50 mm/min) on the tensile and properties of three polymers (high-density polyethylene (HDPE), polypropylene (PP), and polyvinylchloride (PVC)) was studied. A twin-screw extruder was used for the preparation of samples. In order to study the influence of strain rate, tensile strength was used. Mechanical property results show that the tensile properties, tensile strength, and elastic modulus increased with the increase in the strain rate, while elongation at the break point decreased.

Orthoses are commonly used for treating injuries to improve the quality of life of patients, with customized orthoses offering significant benefits. Additive manufacturing, especially fused deposition modelling, enhances these benefits by providing faster, more precise, and more comfortable orthoses. The present study evaluates nine polymeric materials printed in horizontal and vertical directions by assessing their performance through compressive, flexural, and tensile tests. Among all materials, polycarbonate, polylactic acid, and ULTEMTM 1010 showed the most promising results, not only because they had the highest mechanical values, but also due to their minimal or no difference in performance between printing directions, making them advantageous in orthoses fabrication. Based on this, a finite element model of an ankle–foot orthosis was developed to simulate the deformation, strain, and stress fields under static conditions. The findings aim to optimize material selection for orthotic fabrication, where ULTEMTM 1010 is presented as the material with improved performance and durability.

Given the mechanical hazards occurring in the workplace, cut resistance is a particularly important protective parameter. 3D printing is an innovative technology that has recently garnered great interest. It enables the creation of functional polymeric materials with metal reinforcement for use in cut-resistant gloves. The present study characterized and tested 3D-printed polymeric materials intended for such applications. The materials were made from commercially available 3D printing polymer filaments. Metallic reinforcement (stainless steel wire with a diameter of 0.04 mm) was added to the two selected materials (thermoplastic polyurethane and FiberFlex30D). Tests have shown that materials containing metallic reinforcement demonstrate higher mechanical resistance. Cut resistance increased by 70%, and the force needed to tear the sample increased by over 20% compared to the pure polymer. The presence of metallic reinforcement strengthens the structure of the material and changes the cracking mechanism. The tearing occurs in the test area, not in the bell area. These findings demonstrate the feasibility of applying functional 3D-printed polymeric materials with metal reinforcement in cut-resistant gloves. [ABSTRACT FROM AUTHOR]

Speciation analysis is a relevant topic since the (eco)toxicity, bioavailability, bio (geo)chemical cycles, and mobility of a given element depend on its chemical forms (oxidation state, organic ligands, etc.). The reliability of analytical results for chemical species of elements depends mostly on the maintaining of their stability during the sample pretreatment step and on the selectivity of further separation step. Solid-phase extraction (SPE) is a matter of choice as the most suitable and widely used procedure for both enrichment of chemical species of elements and their separation. The features of sorbent material are of great importance to ensure extraction efficiency from one side and selectivity from the other side of the SPE procedure. This review presents an update on the application of polymeric materials in solid-phase extraction used in nonchromatographic methods for speciation analysis. [ABSTRACT FROM AUTHOR]

A problem of modeling plastic injection forming (molding) is presented, including both the plasticizing system of the injection-forming machine and the mold. When modeling the plastic flow in the mold, the input quantities are essentially unknown, e.g., the plastic melt temperature. Thus, a comprehensive (global) model of the injection-forming process is needed for the flow in the plasticizing system and in the mold. The process output quantities from the plasticizing system will be the input quantities for the mold. When modeling the plastic flow in the injection-forming machine, a comprehensive approach should be applied to consider the solid material conveying, material plasticizing, and the material melt flow. The model of material plasticizing is a basis for building such global models. In this research, the effect of the flow (including plasticizing) in the injection-forming machine on the flow in the mold is studied by simulation (using Moldex3D 2023R3OR 64-bit software) and experimentation. These studies are carried out for the injection forming of selected material using a specialized spiral mold. Simulations performed with the use of Moldex3D software for the plasticizing system significantly improved the accuracy of the simulation of the flow in the mold. However, the best results were obtained using experimental data (plastic melt temperature) as input quantities for mold filling simulations. The novel concepts of injection-forming process modeling based on our previous experimentations are also discussed. [ABSTRACT FROM AUTHOR]

The work examines the characteristics of the static and kinetic friction of five types of polymer materials and composites obtained by 3D printing, which are united into 2 groups: group A: PLA, Tough PLA (Technical Polylactic acid), and SteelFill (PLA with stainless steel powder approx. w80%15) and group B: PETG (Polyethylene terephthalate): PETG and CarbonFilTM (PETG with carbon fibers). Results were obtained and analyzed for the variation of the static and kinetic friction force, the static and kinetic coefficient of friction (COF), and the difference between the static and kinetic COF (a jump in COF, known as Stick-slip) from the magnitude of the normal load in two cases of contact with a steel counterbody - without lubricant and with SAE15W40 oil. [ABSTRACT FROM AUTHOR]

The influence of extremely low temperatures on the strength characteristics of adhesive-riveted joints made of aluminum of AMg3M grade with different types of polymeric materials is analyzed. [ABSTRACT FROM AUTHOR]

The paper's aim is to describe the stages of the experimental research as well as the processing of data measured in the SPIF of some polymeric materials using methods such as the Taguchi method, ANOVA analysis, and establishing the regression equation to determine the relevant factors of influence. [ABSTRACT FROM AUTHOR]

The article provides an overview of modern ideas about biodegradation and biodeterioration and of polymer materials. The mechanisms of bacteria sedimentation and attachment and the formation of biofilms are described. Schemes of influencing abiotic and biological environmental factors are considered: the impact of polysaccharides and proteins contained in biofilms on a polymer material, implementation of enzymatic biodegradation reactions, as well as the influence of the material composition and its nature on the tendency to biodegradation. [ABSTRACT FROM AUTHOR]

Purpose. The purpose of this article is to study the influence of the programmable infill structure of material obtained by the additive manufacturing method on their dielectric properties. Methodology. The dielectric characteristics of the test samples were studied by measuring their capacitance and dielectric loss tangent using the RLC meter according to a 4-electrode scheme. The measurements were carried out using alternating current and measuring frequencies of 100 Hz, 1-10-100 kHz. Findings. The relative permittivity is linearly dependent on the specific density and degree of volume filling with high reliability and varies slightly with the measurement frequency. An increase in temperature can change the value of the relative permittivity only in the case of monolithic samples by 2.5% at a temperature of 50℃. The values of the relative permittivity calculated by theoretical models coincide with the measured values for all values of the volume filling. The use of software filling makes it possible to effectively vary the relative permittivity of polylactide material. Originality. It was found that the relative dielectric constant of the polylactide samples under study has a linear dependence on the degree of volume filling. Practical value. It has been established that the use of software filling of prototypes during additive manufacturing allows the creation of materials with adjustable values of the relative permittivity for the creation of products for radio frequency applications. [ABSTRACT FROM AUTHOR]

Raman Spectroscopy has long been expected to aid in clinical decision-making, particularly in the categorization of oncological materials. The intricacy of Raman data has, however, limited its use in therapeutic settings. While conventional machine learning models have made use of this data, new advances in deep learning show promise for furthering the area. In this research, we offer a new machine learning-based technique for detecting tumour precursor lesions in polymeric materials using Raman scattering and nanofabrication. In this case, a spectral analysis based on Raman scattering light intensity was applied to the input tumour picture. The precursor lesion is then elevated using perceptron component analysis using a Kernelization-based convolutional regression. Several skin cancer datasets are analysed experimentally in terms of the F-1 score, area under the ROC curve (AUC), mean squared error (MSE), and precision throughout the training and validation phases. Raman spectral fingerprinting provides an inherent "molecular fingerprint" of a tissue that reflects any biochemical change associated with an inflammatory or malignant tissue state. The proposed method achieved a 95% accuracy in training, a 96% accuracy in validation, a 92% precision, an F-1 score of 90%, an area under the curve (AUC) of 68%, and a MSE of 63%. [ABSTRACT FROM AUTHOR]

Eugenol (4-Allyl-2-methoxy phenol) (EUG) is a plant-derived allyl chain-substituted guaiacol, widely known for its antimicrobial and anesthetic properties, as well as the ability to scavenge reactive oxygen species. It is typically used as a mixture with zinc oxide (ZOE) for the preparation of restorative tooth fillings and treatment of root canal infections. However, the high volatility of this insoluble-in-water component of natural essential oils can be an obstacle to its wider application. Moreover, molecular eugenol can be allergenic and even toxic if taken orally in high doses for long periods of time. Therefore, a growing interest in eugenol loading in polymeric materials (including the encapsulation of molecular eugenol and polymerization of EUG-derived monomers) has been noted recently. Such active macromolecular systems enhance the stability of eugenol action and potentially provide prolonged contact with pathogens without the undesired side effects of free EUG. In this review, we present an overview of methods leading to the formation of macromolecular derivatives of eugenol as well as the latest developments and further perspectives in their pharmacological and antimicrobial applications. [ABSTRACT FROM AUTHOR]

Polymeric materials with excellent performance are the foundation for developing high-level technology and advanced manufacturing. Polymeric material genome engineering (PMGE) is becoming a vital platform for the intelligent manufacturing of polymeric materials. However, the development of PMGE is still in its infancy, and many issues remain to be addressed. In this perspective, we elaborate on the PMGE concepts, summarize the state-of-the-art research and achievements, and highlight the challenges and prospects in this field. In particular, we focus on property estimation approaches, including property proxy prediction and machine learning prediction of polymer properties. The potential engineering applications of PMGE are discussed, including the fields of advanced composites, polymeric materials for communications, and integrated circuits.

Masonry infill walls are commonly used as partitions and exterior walls in many countries. Generally, the masonry wall is executed without any gap from the frame, which leads to the interaction between the structural frame and the infill wall. Interaction between the structural frame and the masonry infill wall can damage the frame and the infill wall. Therefore, it is necessary to find a solution to improve the performance of masonry infill walls in the structural frame. Isolation of the masonry infill wall from the surrounding frame by polymeric material is the idea of this paper to decrease the damage to the structure and masonry infill. In this essay, Finite element models of steel infill frame and isolated infill frame subjected to In-Plane cyclic loading are developed in ABAQUS. For this purpose, three one-bay, one-story masonry-infilled steel frames with different frame ratios of height to the length (H/B) isolated by different polymeric materials with various thicknesses were investigated. Isolation of masonry infill can reduce the base reaction about 25%. In the Isolated Infill wall, the drift’s amount increases about two times compared with the unseparated infill wall. Therefore, it damages the masonry infills up to moderate drifts, while full interaction is still in place drifts are large. Also, infill walls isolated by a softer polymer, have better performance. In brief, isolation of infill wall using polymeric materials improves the behavior of the infill and frame.

Computational modeling (CM) is a versatile scientific methodology used to examine the properties and behavior of complex systems, such as polymeric materials for biomedical bioengineering. CM has emerged as a primary tool for predicting, setting up, and interpreting experimental results. Integrating in silico and in vitro experiments accelerates scientific advancements, yielding quicker results at a reduced cost. While CM is a mature discipline, its use in biomedical engineering for biopolymer materials has only recently gained prominence. In biopolymer biomedical engineering, CM focuses on three key research areas: (A) Computer-aided design (CAD/CAM) utilizes specialized software to design and model biopolymers for various biomedical applications. This technology allows researchers to create precise three-dimensional models of biopolymers, taking into account their chemical, structural, and functional properties. These models can be used to enhance the structure of biopolymers and improve their effectiveness in specific medical applications. (B) Finite element analysis, a computational technique used to analyze and solve problems in engineering and physics. This approach divides the physical domain into small finite elements with simple geometric shapes. This computational technique enables the study and understanding of the mechanical and structural behavior of biopolymers in biomedical environments. (C) Molecular dynamics (MD) simulations involve using advanced computational techniques to study the behavior of biopolymers at the molecular and atomic levels. These simulations are fundamental for better understanding biological processes at the molecular level. Studying the wide-ranging uses of MD simulations in biopolymers involves examining the structural, functional, and evolutionary aspects of biomolecular systems over time. MD simulations solve Newton’s equations of motion for all-atom systems, producing spatial trajectories for each atom. This provides valuable insights into properties such as water absorption on biopolymer surfaces and interactions with solid surfaces, which are crucial for assessing biomaterials. This review provides a comprehensive overview of the various applications of MD simulations in biopolymers. Additionally, it highlights the flexibility, robustness, and synergistic relationship between in silico and experimental techniques.

The development of sustainable flame retardants is gaining momentum due to their enhanced safety attributes and environmental compatibility. One effective strategy is to use waste materials as a primary source of chemical components, which can help mitigate environmental issues associated with traditional flame retardants. This paper reviews recent research in flame retardancy for waste flame retardants, categorizing them based on waste types like industrial, food, and plant waste. The paper focuses on recent advancements in this area, focusing on their impact on the thermal stability, flame retardancy, smoke suppression, and mechanical properties of polymeric materials. The study also provides a summary of functionalization methodologies used and key factors involved in modifying polymer systems. Finally, their major challenges and prospects for the future are identified.