rss_2.0Sciendo RSS Feed for Materials Science-Polandhttps://sciendo.com/journal/MSPhttps://www.sciendo.comhttps://sciendo-parsed.s3.eu-central-1.amazonaws.com/666047fedd1c3d1f87135322/cover-image.jpghttps://sciendo.com/journal/MSP140216https://sciendo.com/article/10.2478/msp-2024-0019<abstract> <title style='display:none'>Abstract</title> <p>The pursuit of effective pain management and wound healing strategies within modern medicine remains a challenge. Postoperative skin injuries arising from surgeries and traumatic incidents often bring substantial discomfort, necessitating interventions that combine optimal pain relief with accelerated wound recovery. In this research, bupivacaine and carica papaya extract were loaded into polycaprolactone/polyvinyl alcohol membranes in order to develop a pain-relieving wound dressing material for pain management and skin wound healing after surgeries. The in vitro experiments were used to characterize the pain-relieving scaffold. An in vivo study of the excisional wound was carried out in a rat model. Histopathological examinations, wound closure studies, and pain-related behavioral factors were utilized to assess the in vivo pain management and wound healing efficacy of the dressings. Results showed that our developed constructs were not toxic and modulated inflammatory responses. In vivo study showed that this system could successfully close wounds and decrease the sensitivity of animals to painful stimuli. These wound dressings may potentially be considered dual function wound dressings to treat skin injuries.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00192024-09-04T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0023<abstract> <title style='display:none'>Abstract</title> <p>Concrete structures are extremely vulnerable to fire damage, which greatly undermines their structural strength and durability. Recently, there has been a concerted effort to develop sustainable concrete materials. Geopolymer concrete (GPC) is a promising substitute for conventional cement concrete due to its use of recycled materials. However, despite the positive effect it has on the environment, GPC is susceptible to heat, which can cause it to deteriorate over time. In response to this issue, the use of carbon-fiber reinforced polymer (CFRP) has been proposed as a means of strengthening heat-damaged GPC. This study aims to investigate the effectiveness of CFRP-strengthened heat-damaged metakaolin-based GPC made from reclaimed asphalt pavement (RAP) aggregate. Three concrete mixtures were used, in which the conventional aggregate was substituted with RAP aggregate at 0%, 25%, and 50% replacement levels. In addition, the concrete cylinders were tested under ambient conditions and subjected to 300°C. The results indicated that the substitution with 25% RAP aggregate significantly reduced compressive strength by 39.1%, while 50% replacement resulted in a 66.8% decrease compared with the control mixture. The use of CFRP sheets to strengthen heat-damaged GPC specimens was proven to be effective in increasing the resistance of the heated specimens and restoring the compressive strength and confinement energy to their original state before reaching the ultimate failure point. The use of CFRP sheets significantly increased compressive strengths, with increases ranging from 87.7% to 368.8% at 26°C and 58.8% to 153.9% at 300°C, compared with each mixture’s unstrengthened control specimen.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00232024-08-30T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0018<abstract> <title style='display:none'>Abstract</title> <p>Dental pulp regeneration has emerged as a promising area of research in dentistry, aiming to restore damaged or diseased dental pulp, which is crucial for maintaining tooth vitality and function. There is a critical need to develop filler materials to treat dental pulp injuries. In the current research, we developed a nanocomposite delivery system for dental pulp stem cells (DPSCs) conditioned media and curcumin-loaded chitosan nanoparticles (CURCNPs) for treating dental pulp tissue injury in a rat model. The delivery system was biocompatible with DPSCs and protected them from oxidative stress. In addition, the developed nanocomposite hydrogel exhibited remarkable anti-inflammatory and anti-oxidative functions. An in vivo study showed that dental pulp tissues treated with hydrogels loaded with the conditioned media and CURCNPs had significantly higher healing activity than other groups. This healing effect was associated with the upregulation of VEGF and TGF-<italic>β</italic> and the downregulation of TNF-<italic>α</italic> and IL-6. In summary, our nanocomposite delivery system, integrating DPSCs conditioned media and CURCNPs, demonstrates promising biocompatibility and remarkable healing potential for treating dental pulp injuries, suggesting clinical applicability.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00182024-08-30T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0024<abstract> <title style='display:none'>Abstract</title> <p>We synthesized a new phenylacetic hydrazide derivative (TAPH) by acylation and amination to prepare modified poly(L-lactide) (PLLA) materials. The non-isothermal melt- and cold-crystallization, melting process, optical and mechanical properties of modified PLLA were studied with the objective of correlating TAPH to PLLA crystallization and other performances. Non-isothermal melt crystallization showed that TAPH as a heterogeneous additive was able to promote crystallization and accelerate the crystallization rate of PLLA. Unfortunately, an increase in the cooling rate during cooling led to a decrease in crystallization ability. Non-isothermal cold-crystallization results disclosed that PLLA/TAPH’s cold-crystallization behavior depended on the heating rate; and upon a given heating rate, with an increase in TAPH loading, a shift toward the low-temperature side of the cold-crystallization peak further confirmed the nucleation effect of TAPH. The melting processes of PLLA/TAPH effectively depended on TAPH, the heating rate, and previous crystallization behaviors including non-isothermal crystallization and isothermal crystallization. Additionally, the double-melting peaks that appeared during the melt were thought to be due to melting-recrystallization. In terms of the optical property, the influence of TAPH on PLLA’s transparency was extremely negative as 2 wt% TAPH caused PLLA’s transparency to be zero. A comparative study on mechanical properties showed that TAPH could enhance PLLA’s tensile modulus and tensile strength, but elongation at break of any PLLA/TAPH was lower than that of pure PLLA.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00242024-08-16T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0022<abstract> <title style='display:none'>Abstract</title> <p>Biomass-derived biochar has gained significant attention due to its unique properties and potential applications in various fields, including asphalt pavement engineering. However, there has been no comprehensive review to date that systematically examines the state-of-the-art research on biochar utilization in asphalt pavements, identifies the key knowledge gaps, and provides recommendations for future research directions. This review aims to fill this gap by providing a novel and critical analysis of the sources and production methods of biochar, the techniques for modifying and characterizing its properties, and its recent applications as an asphalt binder modifier, asphalt mixture additive, and stormwater filter material. The review employs a systematic literature search and analysis methodology, using scientific databases such as Web of Science and Scopus, and keywords related to biochar, asphalt, pavement, and environmental and economic aspects. The selected studies are reviewed and synthesized to identify research gaps, challenges, and future directions, with a focus on the technical, environmental, and economic feasibility of biochar utilization in asphalt pavements. The review also examines the life cycle assessment, carbon sequestration potential, and cost-benefit analysis of biochar utilization. The novelty of this review lies in its holistic approach to assessing state-of-the-art knowledge and its identification of key research needs and opportunities for advancing this emerging field. The review aims to provide valuable insights and recommendations for researchers, practitioners, and policymakers interested in leveraging the benefits of biochar for sustainable and high-performance asphalt pavements.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00222024-08-08T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0020<abstract> <title style='display:none'>Abstract</title> <p>[2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane was synthesized, using triphenylsilane and 1,2-epoxy-4-vinylcyclohexane as the main raw materials. When the molar ratio of triphenylsilane to 1,2-epoxy-4-vinylcyclohexane was 1.0:1.2, the content of Wilkinson catalyst was 0.4%, the reaction temperature was 90°C, and the reaction time was 6 hours, the yield of [2-(3,4-epoxycyclohexyl) ethyl] triphenylsilane could reach 95.21%. The structure of the synthesized product was analyzed and characterized using FT-IR and 1H-NMR. The synthesized product was added to a bisphenol A-type epoxy resin (E-51) and a modified amine (593 amine) to prepare an adhesive. Then, the adhesive was poured into the mold and cured at 35°C for 8 hours. The cured sample exhibited the best performance when the ECETPS: E-51:593 amine molar ratio was 0.8:7.2:2. Thermal gravimetric analysis (TG) showed that the thermal stability of the cured samples increased relative to pure E-51 amine-cured samples with the synthesized product added. The mechanical properties of the samples were tested using a universal material testing machine, and the results showed a tensile strength of 37.95 MPa and a bending strength of 39.10 MPa.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00202024-08-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0021<abstract> <title style='display:none'>Abstract</title> <p>Fire damage poses a significant risk to reinforced concrete structures throughout their lifespan. Fire exposure influences the stress-strain properties and durability of concrete, despite its non-flammability. Therefore, the strengthening approach is an economic option for lengthening their lifespan. This paper aims to conduct an experimental investigation into retrofitting heat-damaged fiber-reinforced concrete cylinders using welded wire mesh (WWM) configurations. Four concrete mixes were investigated. In total, 48 concrete cylinders were tested under axial compression until failure. The primary variables considered in the testing program consisted of (i) the influence of various fiber types (steel fiber (SF), polypropylene (PP), and hybrid fibers (SF+PP)); (ii) exposure temperature (26°C and 600°C); and (iii) WWM strengthening. Exposure to a temperature of 600°C led to a significant reduction in the compressive strength, ranging from 23.7% to 53.3%, while the inclusion of fibers has a substantial effect on the compressive strength of concrete, regardless of fiber type, with an increased ratio reaching up to 34.7%. The finding also clearly shows that the strengthening of heat-damaged specimens with WWM jacketing resulted in a 38.8%, 4.9%, and 9.4% increase in compressive strength for SF, PP, and SF+PPF specimens, respectively, compared to unheated control specimens. The suggested approaches to strengthening, which involve the use of WWM jacketing with two layers, successfully restored and surpassed the initial concrete compressive strength of the specimens that were damaged due to exposure to high temperatures.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00212024-08-01T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0016<abstract> <title style='display:none'>Abstract</title> <sec> <title style='display:none'>Background</title> <p>Osteoarthritis (OA) poses a significant healthcare challenge globally, necessitating the development of effective therapeutic interventions. It is crucial to develop novel drug delivery systems for OA treatment.</p> </sec> <sec> <title style='display:none'>Aims</title> <p>This study explores the potential of propolis, saffron extract, and curcumin-loaded zeolitic imidazolate framework-8 (ZIF8) nanoparticles as a treatment modality for OA. The anti-inflammatory and chondroprotective properties of these natural compounds make them promising candidates for OA management.</p> </sec> <sec> <title style='display:none'>Methods</title> <p>Through comprehensive in vitro investigations, including scanning electron microscopy (SEM), MTT assays, antiinflammatory assays, cell migration assays, Fourier transform infrared (FTIR) spectroscopy, and release assays, we evaluated the physicochemical and biological characteristics of propolis, saffron extract, and curcumin-loaded ZIF8 nanocarriers.</p> </sec> <sec> <title style='display:none'>Results</title> <p>Our findings demonstrate that these nanocarriers effectively encapsulated the bioactive compounds, exhibited sustained release profiles, and displayed significant anti-inflammatory properties. Notably, propolis-loaded ZIF8 nanocarriers exhibited superior anti-inflammatory activity compared to other formulations. The encapsulation of propolis, saffron extract, and curcumin within ZIF8 nanoparticles holds promise for enhancing their therapeutic efficacy and ensuring targeted delivery to affected joints in OA treatment.</p> </sec> <sec> <title style='display:none'>Conclusion</title> <p>This study highlights the potential of nanotechnology-based delivery systems in harnessing the therapeutic benefits of natural compounds for OA management.</p> </sec> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00162024-07-11T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0017<abstract> <title style='display:none'>Abstract</title> <p>18Ni300 is widely used in precision moulds, national defence, and other engineering fields due to its high strength and toughness, and because its properties can be greatly changed after heat treatment. In this research, the 18Ni300 cladding layer was fabricated on 18Ni300 substrate using the laser cladding method and a solid solution artificial aging treatment was carried out to analyse its macro morphology and metallographic organization. Comparison of hardness, friction, and wear of cladding layers manufactured by laser cladding and of materials produced by rolling was performed before and after heat treatment. The results show that the solution and artificial aging heat treatment has a significant effect on the microstructure of the cladding layer fabricated by laser cladding. There are obvious differences in the organization and morphology of different parts of the cladding layer before heat treatment; the metallographic organization and morphology of different parts of the cladding layer after heat treatment are the same. The trend of change of material hardness before and after heat treatment is the same in that the cladding layer is greater than the rolled material and the hardness of the material after heat treatment is much greater than the hardness of the material before heat treatment. The hardness and wear resistance of the material after solution and artificial aging heat treatment has been significantly improved, and the impact on the rolled production material of the melted cladding layer manufactured by laser cladding is even greater.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00172024-06-28T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0005<abstract> <title style='display:none'>Abstract</title> <p>Rheumatoid arthritis is a chronic autoimmune-disease-causing inflammation, joint pain, and joint destruction, severely affecting the quality of life of millions worldwide. In the current research, a nanocarrier system was developed for the delivery of resveratrol and prednisolone to treat rheumatoid arthritis. The drug delivery system was characterized in vitro using scanning electron microscopy and various cell culture studies. Finally, the alleviative symptoms of the developed treatment strategy were investigated in a rat model of rheumatoid arthritis. In vitro studies showed that the carrier system released the drugs in a sustained manner and possessed strong immunomodulatory functions. Nanocarriers loaded with prednisolone, resveratrol, and drug-free carriers had 396.88 ± 76.41 nm, 392.49 ± 97.31 nm, and 338.02 ± 77.75 nm of mean particle size, respectively. In vivo studies revealed that local injection of the carrier system could alleviate the degenerative effects of rheumatoid arthritis. ELISA assays showed that the co-injection of resveratrol and prednisolone-loaded albumin nanoparticles could significantly modulate inflammatory responses. The developed treatment modality may potentially be used to treat rheumatoid arthritis.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00052024-06-28T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0014<abstract> <title style='display:none'>Abstract</title> <p>This research aims to develop sustainable high-strength concrete (SHSC) by replacing 100% fine and/or coarse aggregates with fine recycled aggregate (RA) and/or coarse RA. Due to the high surface water absorption of coarse RA, a surface treatment method was adopted, consisting of immersing it in a cement and silica fume slurry. Moreover, to improve the performance of the produced SHSC, steel fibers were employed at a relatively low volume fraction (0.5%). Eleven blends were cast and tested in this experimental study. A control SHSC mix (without RA) and ten other mixtures, including fine natural and RA, treated and untreated coarse RA, with and without steel fibers, were prepared. Compressive, splitting, and flexural strengths, water absorption, density, and ultrasonic pulse velocity (UPV) of the resulting SHSC were conducted. The results indicated that the use of RA in SHSC resulted in an average drop of 25% in its mechanical properties and an increase of about 30% in water absorption. However, using treated RA compensated the compressive and tensile strength reductions in SHSC by 9% and 7%, respectively, compared to mixes containing untreated RA. On the other hand, adding fibers helped improve compressive, flexural, and splitting tensile strengths by about 8%, 23%, and 31%, respectively, compared to the corresponding control mix. Consequently, the results showed that it is possible to produce durable SHSC made from 100% RA and 0.5% steel fibers with a reduced density and improved mechanical performance to a comparable level or even superior to high-strength concrete (HSC) with only natural aggregates (NAs).</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00142024-06-05T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0006<abstract> <title style='display:none'>Abstract</title> <p>In this work, NiO–ZnOnanocomposite (NC)was prepared through a facile, low-temperature,sol–gel route. Zinc acetate dihydrate, nickel chloride hexahydrate, cetyltrimethyl ammonium bromide (CTAB), and citric acid were used in the synthesis of the material. Then, the sample was kept in the muffle furnace at a temperature of 600°C for 2 h. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), UV–Visible spectroscopy, and photocatalytic and antifungal investigations were used to characterize the synthesized nanocrystallites. The XRD data showedthe polycrystalline hexagonal ZnO nanoparticles and cubic NiO crystallites. FTIR studies confirmed the presence of Zn-O and Ni-O bonds in the sample. The FESEM analysis showed the morphology of nanocrystallitescharacterized by their homogeneous shape and size. The absorbance curves from the UV–Visible spectroscopy investigation revealed the bandgap of 3.17 eV. The research findings demonstrate that the NiO–ZnO NC possesses the significant level of selected microbial pathogens. Industrial dyesmake water unhealthy for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable, and causes a severe threat to human health and environmental safety. Hence, it is necessary to develop efficient and environmentally friendly technology to remove MB from wastewater. The ZnO–NiO NC degraded the MB dye pollutant under visible irradiation (125 W), according to photocatalytic tests. After 120 min of exposure, the photocatalytic investigations demonstrated 75% degradation efficiency.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00062024-05-31T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0011<abstract> <title style='display:none'>Abstract</title> <p>Nanobainitic steels exhibit an exceptional combination of high strength, good plasticity, impact toughness, and wear resistance. They are suitable for the production of large mass components through the open-die forging process. Subsequently, the forgings are air-cooled. An obstacle of this method is the extended time required for the large forgings to undergo a bainitic transformation, making the industrial implementation of this process economically unjustifiable. Nevertheless, nanobainitic steels also allow for the open-die forging of small batches of structural elements with high property requirements. A technological limitation lies in the necessity of performing a series of operations, leading to a prolonged processing time dependent on the shape of the product and the degree of deformation. Therefore, inter-operational reheating is often necessary, incurring costs and time consumption. This is particularly relevant to forgings with a mass ranging from a few to several dozen kilograms, which, due to their low thermal capacity, rapidly dissipate heat to the surroundings and tools. Designing an economical process with a limited number of reheating cycles requires advanced knowledge of material behavior under thermo-mechanical deformation parameters, including boundary conditions where a significant decrease in plasticity occurs and the risk of crack initiation. To obtain this information, a comprehensive analysis of the influence of thermo-mechanical parameters applied during the deformation of nanobainitic steel at relatively low temperatures on the flow characteristics and crack formation was conducted. To achieve this goal, the Digital Image Correlation method, the finite element method modeling considering damage criteria, and the macrostructural evaluation of deformed specimens were employed.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00112024-05-29T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0013<abstract> <title style='display:none'>Abstract</title> <p>Enhancing the service life of natural rubber (NR) products, including antioxidants, is crucial to prevent rubber degradation and enhance its oxidation resistance. Phenolic antioxidant 2246 and cerium complex of p-amino salicylic acid (PAS-Ce) are utilized as NR antioxidants. Numerous studies have qualitatively analyzed the antioxidant mechanisms of these compounds. Building upon this perspective, this study quantitatively assessed the protective mechanisms of these antioxidants by combining experimental data with molecular simulations. Additionally, it compared their impacts on the thermal oxidative aging performance of NR. The findings revealed that the PAS-Ce/NR system exhibited the highest mechanical performance retention following multiple days of thermal-oxidative aging. Analyzing the PAS-Ce/NR system through ATR-FTIR and DTA techniques demonstrated that it had the lowest C=O content after thermal-oxidative aging. Furthermore, calculating the activation energy required for thermal-oxidative aging decomposition using the Kissinger and FWO methods indicated that PAS-Ce/NR had the highest activation energy, suggesting superior inhibitory effects against thermal-oxidative aging. Quantum mechanical simulations also illustrated that the dissociation energy of the O-H bond in antioxidants 2246 and PAS-Ce was lower than that of the C-H bond in NR. However, PAS-Ce exhibited a quicker capture of radical species, effectively delaying the oxidation reaction rate of NR molecular chains and thus more efficiently inhibiting the aging process. These insights contribute significantly to comprehending the antioxidative mechanisms in NR aging.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00132024-05-27T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0012<abstract> <title style='display:none'>Abstract</title> <p>It is essential to retrofit deep beams with shear inadequacies because these beams, although they have the same shear and flexural reinforcements as ordinary beams, are more susceptible to shear failure. Hence, it is of great significance to overcome the shear weaknesses in deep beams. This research paper aims to experimentally examine the effectiveness of near-surface mounted (NSM) carbon fiber reinforced polymer (CFRP) for retrofitting reinforced concrete (RC) deep beams subjected to shear forces. The study involved three different types of specimens. The first specimen was constructed with concrete throughout its span and included shear stirrups. The second specimen was divided into two halves, with one half lacking shear reinforcements and the other half having them. The third specimen had steel web reinforcement in one half of the span, while the other half was strengthened using NSM CFRP U-wrap strips and externally bonded horizontal CFRP strips. The proposed strengthening method significantly increased the shear strength of the deep beams, surpassing that provided by steel web reinforcement alone. Furthermore, the NSM CFRP strengthened specimen exhibited a change in failure mode from shear to flexural failure. In comparison to the control beam without stirrups, the beams strengthened with NSM CFRP U-wrap strips demonstrated an impressive 82% improvement in shear strength, while the beam with shear reinforcement showed a 23 % enhancement in load capacity. The proposed strengthened scheme is capable of enhancing the structural performance and load-carrying capacity effectively. A finite element model was generated utilizing ABAQUS software to simulate the behavior of the tested deep beams and verified against the experimental outcomes. The numerical models successfully predicted the behavior of the RC deep beams strengthened with NSM CFRP when compared to the experimental data.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00122024-05-27T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0008<abstract> <title style='display:none'>Abstract</title> <p>The KOBO extrusion process is an unconventional method of extrusion based on the phenomenon of superplasticity as an effect of a special state caused by the oscillatory motion of the die at a certain angle a certain frequency. It significantly lowers the extrusion force and makes it possible to extrude lightweight metals and alloys (e.g. aluminum and magnesium alloys) in cold extrusion with high extrusion ratios compared to conventional hot extrusion.</p> <p>This work studies the influence of the tool (die) geometry on process realization parameters and the properties of the extrudate. Experimental studies of cold KOBO extrusion were performed using dies with different face portion geometry. The obtained extrudate obtained from EN-AW 7075 aluminum billets was examined for mechanical properties and macro/microstructure, showing that, with adequate modifications to the tool face part geometry, it is possible to lower the extrusion force and obtain extrudate with desired properties.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00082024-05-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0010<abstract> <title style='display:none'>Abstract</title> <p>Sulfate attack is one of the most significant durability issues for cement-based grouts, which are widely used to repair concrete structures in sulfate-rich environments. The purpose of this study was to investigate the impact of nano-SiO₂ emulsion on the sulfate resistance of cement-based grouts. The durability of the mixes was evaluated on the basis of weight loss and compressive strength. X-ray diffraction (XRD) and scanning electron microscopy (SEM) of hardened grout matrix were used to analyze the hydration products and microstructure of the hardened grout matrix. The results indicate that the hydration degree of nano-SiO₂-modified samples is higher than that of the control sample. The compressive strength from highest to lowest was 16 NSE, 10 NSE, NSP, and the control sample. The XRD and SEM results suggest that the deterioration of properties may be attributed to the formation and growth of ettringite (AFt) crystals, which may result in crack generation and extension and in the corrosion of gypsum, leading to exfoliation. The addition of nano-SiO₂ to cement-based grouts through a preprepared emulsion, which facilitates dispersion within the cement matrix, has the potential to reduce AFt and gypsum contents, enhance microstructure density, decrease the migration channels of <inline-formula><alternatives><inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/j_msp-2024-0010_ieq_001.png"/><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mtext>SO</mml:mtext></mml:mrow><mml:mn>4</mml:mn><mml:mrow><mml:mn>2</mml:mn><mml:mo>−</mml:mo></mml:mrow></mml:msubsup></mml:mrow></mml:math><tex-math>\[\text{SO}_{4}^{2-}\]</tex-math></alternatives></inline-formula>, and ultimately improve the resistance to sulfate attack. This work will provide a novel route to enhance the sulfate resistance of cement-based grouts, which may be serviced in a sulfate-rich environment.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00102024-05-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0007<abstract> <title style='display:none'>Abstract</title> <p>This paper focuses on the development of a technological challenges of manufacturing the planar ceramic vacuum sensor based on the principles of hot-cathode ionization in the Bayard-Alpert configuration. The goal is to simplify the technological process by utilizing planar platinum structures with gold electrical paths instead of 3-dimensional structures. Various methods were tested, including the use of carbon-based SVM (Sacrifice Volume Materials) materials, but without success. Wet-etching using potassium hydroxide on Al₂O₃ substrates showed promise results. The findings highlight the challenges and progress made in developing the thermo-emittercomponent of the vacuum sensor.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00072024-05-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0009<abstract> <title style='display:none'>Abstract</title> <p>Carbon dots (CDs) are emerging as versatile fluorescent nanoprobes for bioimaging applications due to advantages like tunable emissions, excellent biocompatibility, facile surface functionalization, and ease of synthesis. This review summarizes recent advances in applying biosynthesized CDs for sensitive bioimaging. CDs derived from sustainable biomass sources through green techniques like hydrothermal and microwave synthesis demonstrate bright, excitation-tunable photoluminescence spanning visible to near-infrared spectra. Careful control of synthesis parameters and surface passivation strategies enhance quantum yields above 50% comparable to toxic semiconductor dots. Conjugation with polymers, peptides, and recognition elements like antibodies impart solubility and selectivity towards cancer cells and biomarkers. <italic>In vitro</italic> validation in standard lines shows targeted organelle imaging abilities. <italic>In vivo</italic> administration reveals renal clearance pharmacokinetics with preferential tumor accumulation via enhanced permeability effects. Average tumor growth inhibition around 50-80% was achieved in mouse xenografts using CDs-drug formulations through combined therapeutic effects of chemotherapy and photothermal ablation under imaging guidance. However, concerns regarding toxicity from chronic exposures, large-scale reproducible manufacturing, and multimodal imaging capabilities need redressal prior to further clinical translation.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00092024-05-22T00:00:00.000+00:00https://sciendo.com/article/10.2478/msp-2024-0002<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this work was to carry out comparative studies of WC-Co-Cr coatings deposited using the high velocity oxy fuel (HVOF) method onto two types of substrate material: structural steel S235 and magnesium alloy AZ31. The influence of the substrate material type on the microstructure, phase composition, crystallite size, porosity, Vickers microhardness, instrumental hardness (H_IT), Young’s modulus (E_IT), and fracture toughness was investigated. For both substrates, the deposited coatings deposited were characterized with fine-grained and compact microstructure. The X-ray diffraction (XRD) revealed presence of following phases: WC, W₂C, Co_0.9W_0.1, and Co₃W₉C₄. The WC phase was the most desirable and stable one with crystallites were below 100 nm. On the other hand, the size of the W₂C crystallites was below 30 nm. The coatings obtained showed porosity values equal to 2.3 ± 0.4 vol% and 2.8 ± 0.7 vol% for AZ31 and S235, respectively. The average Vickers microhardness for both types of sample was appproximately 1200 HV0.3. The average H_IT values for carbide particles and metallic matrix were around 29 GPa and 6.5 GPa, respectively. In the case of E_IT, it was around 620 GPa and 190 GPa for WC and Co-Cr, respectively. The differences between coatings were negligible. The E_IT value for both coatings was equal to 344 ± 11 GPa. The fracture toughness was around 4.5 MPa · m^1/2 in both cases. The investigations revealed that it is possible to replace steel substrate material with a much lighter equivalent, in this case AZ31 alloy, without deterioration of the coating properties.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/msp-2024-00022024-05-08T00:00:00.000+00:00en-us-1