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Today’s environment is under the influence of numerous substances and most of them are not covered by current national and international regulations. Substances that are classified as contaminants of emerging concern, CECs, are not regulated nor systematically controlled in the environment, and they belong to the different chemical classes such as pesticides in current use, pharmaceutically active compounds (PhACs), personal care products, illicit drugs, hormones, micro- and nano-plastics, per- and poly-fluoroalkyl substances (PFAS), and many others. Once released CECs end up in surface water where they can be either accumulated or transported to the other environmental compartments, i.e. soil (by irrigation), underground water, or drinking water. The aim of the research was to investigate the efficiency of different selected solid-phase extraction (SPE) cartridges for preparation of water samples for simultaneous analysis of several CECs. For this purpose, a model mix solution of selected CECs in concentration relevant to environmental appearance was used. The selected CECs (14 PhACs, 11 pesticides in current use, and 4 PFAS) represented emerging contaminants with different properties, including polarities, and varying adverse effect on the environment and human health. Different types of sorbents were investigated: (i) commercial single-layer HLB, (ii) homemade multi-layer I: HLB plus a mix of WAX, WCX, and PPL, and (iii) multi-layer II: mix of WAX, WCX, and PPL plus HLB. The results revealed that the single-layer sorbent showed better efficiency in extraction of the analyzed CECs. Multi-layer sorbent should be further investigated to elucidate the possible reason for the poor extraction of some compounds, as development of a balanced extraction for a wider range of contaminants with different polarities, especially for non-target analysis of chemical residues, is required in order to capture the occurrence of the full profile of micropollutants.

The leading export product of Hungary is canned sweetcorn, which is available in single-component or blended varieties with a focus on colour retention, for wich the food industry mainly uses ascorbic acid and EDTA in the brine of canned vegetable. Thoughtful customer behavior is pushing the food industry to switch to natural plant extracts instead of synthetic additives. In order to investigate if acerola plant extract is suitable as a replacement for ascorbic acid, we investigated the potential uses of two varieties of acerola extract in three different concentrations in the case of canned mixed sweet corn and red bean. After production, and after 1 week of thermostating at 55°C and storage at room temperature for 4 and 8 weeks, the changes in pH value, salt concentration, water-soluble dry matter content, colour, total polyphenol content, and antioxidant capacity of the brine were all evaluated in this experiment. The results showed that both acerola extracts were promising in fixing the colour, with the higher application of the first extract and the lowest and highest dosage of the second extract showing the best results. During storage, the polyphenol content and antioxidant capacity of some samples decreased slightly compared to their initial values.

The 3D printing technology involves a digital manufacturing machine that produces three-dimensional objects according to designs created by the user via 3D modelling or computer-aided design/manufacturing (CAD/CAM) software. This work analyzes the processing timeline of the filament (material for 3D printing) from unboxing to the extrusion trough the nozzle. It is an important task to analyze the growth of bacteria on 3D printed surface and in gaps between the layers. By default, 3D printed object is not food safe after longer usage and direct contact with food (even though the food safe filaments were used), but there are solutions for this problem. We tested several methods to prevent or reduce the emerging microbial contamination. These methods are coating with epoxy resin, using antimicrobial and high temperature-resistant filaments. The best results were obtained by epoxy resin coating, where the object was cleanable like any other injection molded plastic object with smooth surface. Very good results have also been obtained by boiling the objects, and it is good to see that nowadays more and more special filaments have food safe certificate and can withstand boiling temperatures too. Using antibacterial filaments reduced bacterial colonies by 80%, which is not a perfect solution.

Inventory management has a different meaning in agriculture than in a commercial chain, but it is just as important. In most cases, the purpose of the inventory is to satisfy demand. Demand and supply do not always meet at a predetermined place and time but are shaped by external circumstances. It is the same in agriculture. Our research aims to present and compare simple inventory management methods through a practical agricultural example and to examine the ethical aspects. To manage inventory, we have to make an appropriate decision in the following two questions: when to order and how much to order. There are three basic inventory mechanisms: cycle inventory, damping inventory, and two-warehouse inventory. There are three levels within business ethics: macro-, meso-, and micro-level. In the case of the examined agricultural limited company, the meso- and micro-levels are affected by ethical problems. When handling inventory improperly, can the employee be held liable, or is the company responsible? The agricultural sector began to develop, which is mainly the result of developments in the use of information technology. Even so, many farms still use outdated methods, which should be changed to operate more economically

In industrialised countries, around 670 million tonnes of food are lost every year, much of it still fit for human consumption. Due to the special nutrient management of organic farming, root vegetables have a higher dry matter content and a lower nitrate content, which also affects their shelf-life. The effect of storage under domestic conditions was investigated in our experiments on organic and conventional carrot lots. It was found that packaged organic carrots in a 4°C environment showed the longest shelf life, lowest nitrate content and weight loss during household storage. The results of the experiment may contribute to lower food waste through changes in consumer habits.

Statistical tests like t test are used to test the hypothesis for comparison of mean between two groups. The result from a t test is used to determine if there a significant difference between the two samples mean, which cannot be attributed to sampling error or to random occurrence. A t test is considered a parametric test, meaning test samples should meet assumptions of normality, equal variances and independence. The article aims to calculate the power of unpaired t test using simulation in Microsoft Excel.

The presence of different bird species in inhabited areas is becoming increasingly common. The problem with these species is that they are more likely to spread pathogens, contaminate public and private land with their droppings, cause economic damage or even frighten the public. One of the most notable conflict species causing environmental pressures in populated areas is the feral pigeon (Columba livia f. domestica), whose populations are increasing worldwide. Adequate practices and methods are available to reduce the problem. However, their applicability and effectiveness may vary from one locality to another due to the different characteristics of the localities and the different causes of the pigeons' presence. Therefore, it is essential to think in terms of town-specific solutions, the preparation of which requires, among other things, an assessment of the temporal and spatial pattern of occurrence of the species causing the conflict, an understanding of the extent of damage and an overview of the population's level of information. In our study, we investigated the environmental pressures of the feral pigeon in the historical city centre of Sopron, using a combination of the three elements mentioned above. For this purpose, we carried out a monthly visual population assessment combined with a photographic technique at sample points for one year. We conducted a field visit to the area to draw up a damage map of the study area and a spatial localisation of existing control methods. Questionnaire surveys complemented this to assess the public's awareness of the issue. In light of the results, we drew up a map of the pigeon conflict in the city centre of Sopron and identified possible solutions.

Green hydrogen, using renewable electricity that breaks down water molecules into hydrogen and oxygen, holds great promise for meeting global energy demand while contributing to climate policy goals. Interest in green hydrogen production technologies has increased considerably. This is because the potential uses of hydrogen cover many sectors, including power generation, manufacturing processes in steel and cement production, fuel cells for electric vehicles, and power grid stabilization. One possible use of green hydrogen is to blend it with natural gas and deliver it to end-users using existing natural gas pipeline storage and networks, thereby increasing performance and reducing emissions. In the case of underground storage of a hydrogen natural gas mixture, it is important to assess its impact on the reservoir beforehand, which rock permeability studies can do. This article deals with the theory of rock permeability testing for natural gas and natural gas-hydrogen mixtures.

The goal of gasification is the conversion of solid fuels or carbonaceous wastes to gas that can be further used energetically or for chemically utilisation. Due to cost-effectiveness and gaining experience, the industrial application of new systems and raw materials or mixtures must be preceded by laboratory-scale experiments. The manuscript presents the laboratory scale gasification systems we designed and used, as well as the difficulties experienced during the implementation (e.g. water introduction, sealing, etc.). In addition to these, the results of one-, two- and three-stage experiments are presented as examples, where different materials such as a mixture of wood and canteen waste, brown coal and refuse derived fuel (RDF) were used for testing the system.

In this research, a lactic acid-based biodegradable polymer (polylactic acid, PLA) was chemically modified and the mechanical material property changes were studied. The hardness and elastic modulus were determined with a nanoindentation instrument. The modified PLA was compared to the unmodified control group. Each group contained 5 different samples and t-test was performed to compare the mean difference of the hardness and elastic modulus between the two groups. A statistically significant result was obtained both in the hardness and elastic modulus due to the modification. The treated sample structure has become more inhomogeneous as well. The elastic modulus of the modified PLA reduced in its hardness and elastic modulus compared to the control PLA.

In my research work, I primarily focused on the investigation of yogurt (made from home-made raw milk) spoilage by microbiological and dielectric measurements. During the experiment, I continuously monitored the changes in aerobic and anaerobic Lactobacillus cell counts of the product, as a possible spoilage process would cause the deteriorative microbes to displace the lactic acid bacteria, and I also monitored the changes in the dielectric properties of the sample material at 400 MHz frequency. The research results verified that there is a strong correlation between the variation in live cell counts and dielectric parameters in both aerobically and anaerobically cultured lactic acid bacteria. The main conclusions of the results are that the change in the bacterial count, and thus the deterioration process leading to it, can be indirectly monitored in the dairy product under study by low-frequency determination of both the dielectric constant and the loss factor.

Nowadays, instead of traditional wheat grains, alternative cereals, also known as pseudocereals, are increasingly coming to the fore. The reason for this is, among other things, that more and more people struggle with food allergies and intolerances. Gluten-related disease - such as gluten sensitivity - is a chronic disease of the small intestine with malabsorption, which is triggered by gluten, a vegetable protein found in certain cereals, in people who are sensitive to it. Because of this, the demand for foods in which alternative gluten-free pseudocereals play a prominent role has understandably increased. Our research and development goal was aimed at getting to know and examining the different raw materials and their functional enrichment possibilities, which has led to the development of a new range of pasta products.

The basis of the long-term success of dental implants is the mechanical stability of the implant and the superstructure anchored in it. In order to investigate the mechanical behaviour of the conical connection in implant-abutment units, static and dynamic load tests were performed with different conical angles and various Grade 4-5 titanium implant materials. The assembled units were mounted in self-developed loading machine and in an Instron ElectroPuls E3000 fatigue machine. For static loading, the samples were loaded with a force from 0 N to 500 N in steps of 100 N. For dynamic loading, the samples were loaded for 30,000 cycles with a force of 250 ± 150 N. In case of static testing, the compression caused by the load was measured in both horizontal and vertical directions, while in the case of dynamic fatigue, only horizontal deformation was defined. In both cases, the drive-out (reverse) torque values of the fixing screws were determined after loading. No significant differences were found between the tested materials in the reverse torque after the static load, however, significant differences were shown with regards to the alterations in cone angle (p < 0.001). After dynamic loading, significant differences (p < 0.001) were also observed between the reverse torques of the fixing screw in different angles. The static and dynamic test results showed the same tendency: under the same load conditions, the conical angle value of the implant-abutment connection revealed significant differences in the loosening of the fixing screw. In summary, it is recommended to use higher conical angle connection to avoid larger deformations in lengths and diameters of the implant at the connection and essential torque reduction of the fixing screw. Our results may contribute to the understanding of the long-term success of dental implants.

The food industry has been at the forefront of rapid implementation for several technological innovations. One of the main reasons for this is that food security has been of paramount importance in supplying a growing population, taking into account both quantitative and qualitative requirements. And the necessary development could only be ensured by incorporating the latest developments. Blockchain technology is also a tool to consider in terms of how it can help track food chains. Its widespread application is only a decade old, but in some areas, for example, the operation of cryptocurrencies has already accumulated enough experience to see if it really lives up to the hopes attached to it, and what problems still stand in the way of further spread. With this material, our primary goal is to present a significant technological change that aims to solve one of the main problems of blockchain-based data management. It will be presented how the technology works (with a specific focus on the proof of work mechanism) and the transition to a truly significant platform, the proof of stake mechanism at Ethereum. This gives us an idea of how much a relatively new technology can undergo changes, and at what rate a seemingly significant problem (in this case, e.g. environmental impact) can decrease. This potential for development provides the basis for counting blockchains as a technology that can be applied in other areas, such as the food industry. In addition to scientific treatises, we often rely on Internet sources in the material, since the change occurred so quickly that publications in scientific journals could not yet track it or only in a narrower circle.

In Hungary, viticulture and winemaking have a very long tradition and culture. Nowadays, more and more consumers are paying attention to the nutritional properties of the food they consume, in addition to their enjoyment value. Wines can have an outstanding antioxidant content. The amount of antioxidants can be influenced by a number of parameters (wine-making technology, grape variety, area under vines, etc.). Antioxidants play an important role in the preservation of health, as well as inhibiting oxidation processes in food. Dielectric material analysis methods are also increasingly used in the food industry. The great advantages of dielectric testing include its chemical-free nature and the speed of the test. In our studies, we have investigated the food properties, i.e. alcohol, acid and antioxidant content and dielectric properties of different wine samples

Phytomining of rare earth elements (REEs) provides a potential possibility for metal recovery at brownfields where conventional mining technique is not reasonable or profitable. The holistic concept of phytomining is instituted from three scientific sectors. Phytoextraction is the first stage referred to accumulation of REEs in plants. This is followed by the enrichment process aiming to elevate metal concentration into solid remains. Eventually, extraction technology is applied to reclaim these valuable metals from the bio-ores. The main goal of this study is to identify a possible location for REEs phytomining, which lays the groundwork for further investigations. To do that, different woody biomass from disparate contaminated spots was harvested and examined. A brownfield land located in Gyöngyösoroszi, Hungary has been selected based on the elemental analysis of ash samples obtained from the incineration of the collected plants at 500 °C. The outcomes also preliminarily indicate the viability of phytomining in recovering REEs.

It is demonstrated that the application of piezoelectric sensors to metallic bars and strands can enable determining the status of the integrity of these elements through the spectrum of their acoustic excitations. The voltage output of the piezo, secured to metal bars or strands, is fed to the input of a Fast Fourier Transform analyzer, which allows displaying the spectrum of the excitations from which information on the length, overall quality of the metal, and the presence of defects can be obtained. We show that the analysis, performed on several materials and strands of different lengths, could be useful for cases in which visible inspection and/or direct access to the entire body of the metallic elements is not possible. Applications of our study for testing metallic structures embedded in concrete foundations are reported for construction sites.

Metal halide perovskite semiconductors have emerged as promising materials for various optoelectronic applications due to their unique crystal structure and outstanding properties. Among different forms, perovskite nanowires (NWs) offer distinct advantages, including a high aspect ratio, superior crystallinity, excellent light absorption, and carrier transport properties, as well as unique anisotropic luminescence properties. Understanding the formation mechanism and structure–property relationship of perovskite NWs is crucial for exploring their potential in optoelectronic devices. In this study, we successfully synthesized all-inorganic halide perovskite NWs with high aspect ratios and an orthorhombic crystal phase using the hot-injection method with controlled reaction conditions and surface ligands. These NWs exhibit excellent optical and electrical properties. Moreover, precise control over the halogen composition through a simple anion exchange process enables the tuning of the bandgap, leading to fluorescence emission, covering a wide range of colors across the visible spectrum. Consequently, these perovskite NWs hold great potential for efficient energy conversion and catalytic applications in photoelectrocatalysis.

The use of thermoplastic composites (TPCs) as one of the lightweight solutions will inevitably encounter problems in connection. Resistance welding has the characteristics of high strength, simplicity, and high reliability, and is considered a very potential hot-melt connection technology. The resistance welding technology of unidirectional carbon fiber-reinforced polyphenylene sulfide composites (UCF/PPS) was systematically studied. The experimental results show that the 100-mesh brass mesh has the best resin wetting effect and heating efficiency, and the PPS/oxidized 100-mesh brass mesh composite resistance element (Ox-RE/PPS) has the highest welding strength. The welding failure mode changes from interface failure and RE failure to interlayer structure damage and fiber fracture. The single-factor experimental results show that the maximum welding strength is reached at 310 °C, 1.15 MPa, and 120 kW/m2. According to the conclusion of the single-factor experiment, the Box–Behnken method was further used to design a three-factor, three-level experiment, and a quadratic regression model was established according to the test results. The results of variance analysis, fitting curve analysis, and perturbation plot analysis proved that the model had high fitting and prediction abilities. From the 3D surface diagram analysis, the influence of power density is the largest, and the interaction between welding temperature and power density is the most significant. Combined with the analysis of Design Expert 13 software, the optimal range of process parameters was obtained as follows: welding temperature 313–314 °C, welding pressure 1.04–1.2 MPa, and power density 124–128 kW/m2. The average strength of resistance welding joints prepared in the optimal range of process parameters was 13.58 MPa.

In the realm of material science and engineering, the pursuit of lighter, stronger, and more durable materials has been an enduring quest [...]

Both microvoids and helium (He) impurities are widely present in tungsten (W) plasma-facing materials (PFMs), where the interaction between microvoids and He atoms has led to the intriguing development of microvoids. In this paper, we comprehensively investigated the interaction between He atoms and trivacancy (V3), a fundamental microvoid in W-PFMs, at the level of tight-binding theory. Our study showed that He atoms can catalyze the decomposition of the original V3 or facilitate its transformation into another V3 variant. We propose that a He atom near the V3 defect induces significant changes in the distribution of d-electron charges within the W atoms lining the inner wall of the V3 defect, making the W atom nearest to this He atom cationic and the other W atoms anionic. The attractive interaction between them promotes the decomposition and deformation of V3. As electronic excitation increases, the ionization of W atoms on the V3 wall gradually intensifies, thereby enhancing the cationic characteristics of the W atoms closest to the He atom. This process also prompts other W atoms to shift from anions to cations, leading to a transition in the electrostatic interactions between them from attraction to repulsion. This transformation, driven by electronic excitation, plays a significant inhibitory role in the decomposition and deformation of V3.

The concept of ecology, historically rooted in the economy of nature, currently needs to evolve to encompass the intricate web of interactions among humans and various organisms in the environment, which are influenced by anthropogenic forces. In this review, the definition of ecology has been adapted to address the dynamic interplay of energy, resources, and information shaping both natural and artificial ecosystems. Previously, 3D (and 4D) printing technologies have been presented as potential tools within this ecological framework, promising a new economy for nature. However, despite the considerable scientific discourse surrounding both ecology and 3D printing, there remains a significant gap in research exploring the interplay between these directions. Therefore, a holistic review of incorporating ecological principles into 3D printing practices is presented, emphasizing environmental sustainability, resource efficiency, and innovation. Furthermore, the ‘unecological’ aspects of 3D printing, disadvantages related to legal aspects, intellectual property, and legislation, as well as societal impacts, are underlined. These presented ideas collectively suggest a roadmap for future research and practice. This review calls for a more comprehensive understanding of the multifaceted impacts of 3D printing and the development of responsible practices aligned with ecological goals.

To understand the fracture properties of the nitrate ester plasticized polyether (NEPE) propellant, single-edge notched tension (SENT) tests were carried out at room temperature (20 °C) under different tensile rates (10–500 mm/min). The mechanical response, crack morphology, evolution path, and crack propagation velocity during the fracture process were studied using a combination of a drawing machine and a high-speed camera. The mode I critical stress intensity factor KIc was calculated to analyze the tensile fracture toughness of the NEPE propellant, and a criterion related to KIc was proposed as a means of determining whether the solid rocket motors can normally work. The experimental results demonstrated that the NEPE propellant exhibited blunting fracture phenomena during crack propagation, resulting in fluctuating crack propagation velocity. The fracture toughness of the NEPE propellant exhibited clear rate dependence. When the tensile rate increased from 10 mm/min to 500 mm/min, the magnitude of the critical stress intensity factor increased by 62.3%. Moreover, numerical studies based on bond-based peridynamic (BBPD) were performed by modeling the fracture process of the NEPE propellant, including the crack propagation speed and the load–displacement curve of the NEPE propellant. The simulation results were then compared with the experiments.

While binder jetting (BJ) additive manufacturing (AM) holds considerable promise for industrial applications, defects often compromise part quality. This study addresses these challenges by investigating binding mechanisms and analyzing common defects, proposing tailored solutions to mitigate them. Emphasizing defect identification for effective quality control in BJ-AM, this research offers strategies for in-process rectification and post-process evaluation to elevate part quality. It shows how to successfully process metallic parts with complex geometries while maintaining consistent material properties. Furthermore, the paper explores the microstructure of AISI M2 tool steel, utilizing advanced image processing techniques like digital image analysis and SEM images to evaluate carbide distribution. The results show that M2 tool steel has a high proportion of M6C carbides, with furnace-cooled samples ranging from ~2.4% to 7.1% and MC carbides from ~0.4% to 9.4%. M6C carbides ranged from ~2.6% to 3.8% in air-cooled samples, while water-cooled samples peaked at ~8.52%. Sintering conditions also affected shrinkage, with furnace-cooled samples showing the lowest rates (1.7 ± 0.4% to 5 ± 0.4%) and water-cooled samples showing the highest (2 ± 0.4% to 14.1 ± 0.4%). The study recommends real-time defect detection systems with autonomous corrective capabilities to improve the quality and performance of BJ-AM components.

In order to overcome the problems of the high economic and environmental costs of a traditional ordinary portland cement-based binder, this study used self-combusted coal gangue (SCCG), granulated blast furnace slag (GBFS) and phosphorous slag (PS) to prepare a novel SCCG-GBFS-PS (SGP) ternary alkali-activated binder for solidifying silty soft clay (SC). Firstly, the parameters of the SGP ternary binder were optimized using orthogonal experiments. Then the effects of the SGP ternary binder content (mass ratio of the SGP ternary binder and the SGP-solidified soil), initial water content of SC (mass ratio of SC’ water and SC) and types of additives on the unconfined compressive strength (UCS) of the SGP-solidified soil were analyzed. Finally, the hydration products and microstructure of the SGP-solidified soil were analyzed to investigate the solidification mechanism of the SGP ternary binder. The results showed that the optimal mass ratio of GBFS and PS is 2:1, and the optimal alkali activator content (mass ratio of Na2O and the SGP ternary binder) and modulus of alkali activator (molar ratio of SiO2 and Na2O of alkali activator) were 13% and 1.3, respectively. When the SGP ternary binder content was 16% and the initial water content of SC was 35%, the SGP-solidified soil met the requirement of UCS for tertiary cured soil. The incorporation of triethanolamine and polyvinyl alcohol improved the UCS, while the incorporation of Na2SO4 significantly deteriorated the UCS of the SGP-solidified soil. The C-S-H gels and C(N)-A-S-H gels generated by hydration of the SGP-solidified soil were interspersed, interwoven and adhered to each other to form a network-like space structure that played the roles of skeleton, bonding soil particles and filling pores, which improved the macroscopic properties of the SGP-solidified soil. The results of this study provide a reference for the design and development of a solid waste-based binder for solidifying SC.

The experimental and numerical simulation analysis of a TiAl alloy by laser metal deposition technology is presented in this paper. The research examines the macroscopic morphology, microstructure, and mechanical properties of samples as laser power varies. It also delves into how the temperature field and residual stress evolve under different laser powers. The results reveal that the microstructure of samples is mainly composed of α2-Ti3Al phase and a γ-TiAl phase and that the details of the microstructure are significantly affected by laser power. As laser power increases, coarse lamellar structure content increases, corresponding to a decrease in α2 phase content. The deposited layer hardness ranges from 550 HV to 600 HV, and the average deposition layer hardness decreases with increased laser power. Simulation results predict the molten pool’s size, temperature, and residual stresses. A significant increase in the molten pool size is observed when the laser power exceeds 1000 W, and the measured molten pool depths correspond closely to simulation predictions. However, significant tensile stresses are generated in the deposition layer due to high cooling rates, mainly in the x direction. Cracks are observed on the surface of the deposition layer at all laser powers.

The inductive heating of a CMC susceptor for industrial applications can generate very high process temperatures. Thus, the behavior of a silicon carbide-based matrix with carbon-fiber-reinforced carbon (C/C-SiC) as a susceptor is investigated. Specifically, the influence of fiber length and the distribution of carbon fibers in the composite were investigated to find out the best parameters for the most efficient heating. For a multi-factorial set of requirements with a combination of filling levels and fiber lengths, a theoretical correlation of the material structure can be used as part of a digital model. Multi-physical simulation was performed to study the behavior of an alternating magnetic field generated by an inducing coil. The simulation results were verified by practical tests. It is shown that the inductive heating of a C/C-SiC susceptor can reach very high temperatures in a particularly fast and efficient way without oxidizing if it is ensured that a silicon carbide-based matrix completely encloses the fibers.

The crack resistance of concrete structures with low reinforcement ratios requires a broader examination. It is particularly important in the case of foundations working in changing subsoil conditions. Unfavorable phenomena occurring in the subsoil (e.g., ground subsidence, landslips, non-uniform settlement) can lead to unexpected cracking. Therefore, it is necessary to check the effectiveness of the low reinforcement provided. As there are limited studies on lightly reinforced concrete structures, we performed our own experimental investigation and numerical calculations. In the beams analyzed, the reinforcement ratio varied from 0.05% to 0.20%. It was found that crack resistance in concrete members depends on the reinforcement ratio and steel bar distribution. A comprehensive method was proposed for estimating the crack resistance of lightly reinforced concrete members in which both the reinforcement ratio and the reinforcement dispersion ratio were taken into account. Furthermore, the method considered the size effect and the fracture properties of concrete. The proposed method provides the basis for extrapolation of the test results obtained for small elements and conclusions for members with large cross-sections, such as foundations, which frequently use lightly reinforced concrete.

An alkali–silica reaction (ASR) is a chemical process that leads to the formation of an expansive gel, potentially causing durability issues in concrete structures. This article investigates the properties and behaviour of ASR products in mortar with the addition of low-purity calcined clay as an additional material. This study includes an evaluation of the expansion and microstructural characteristics of the mortar, as well as an analysis of the formation and behaviour of ASR products with different contents of calcined clay. Expansion tests of the mortar beam specimens were conducted according to ASTM C1567, and a detailed microscopic analysis of the reaction products was performed. Additionally, their mechanical properties were determined using nanoindentation. This study reveals that with an increasing calcined clay content, the amount of the crystalline form of the ASR gel decreases, while the nanohardness increases. The Young’s modulus of the amorphous ASR products ranged from 5 to 12 GPa, while the nanohardness ranged from 0.41 to 0.67 GPa. The obtained results contribute to a better understanding of how the incorporation of low-purity calcined clay influences the ASR in mortar, providing valuable insights into developing sustainable and durable building materials for the construction industry.

The work presents a detailed analysis of the possibilities of the thermal processing of clay raw material granulates in a fluidized bed reactor powered by coal fuel. Potential customers of calcined granulates include the following: plants producing refractory materials for the steel industry, producers of refractory concrete, sanitaryware plants, tile plants, large-size tile plants, industry abrasives, chemicals, paints, paper, food and medical industries and others. The advantage of the presented fluid bed calcination technology is the possibility of the continuous operation of the reactor and the short time of the material in the bed, compared to the previously used methods of calcination in a shaft and rotary kiln, which lasts less than twenty minutes in the temperature range of 650–850 °C. During the experimental studies of calcination in the fluidized bed layer, the influence of the type of coal, its particle size and the mass share of coal in the feed mixture on the calcination process and the final product obtained was analysed. As a result of the conducted research, it was proven that solid fuels such as anthracite and steam coal type 31.2 (flaming) can be successfully used in the fluidized bed calcination process of clay materials. The key parameter determining the fluidized bed calcination process is the fuel particle distribution.

Cellular materials offer industries the ability to close gaps in the material selection design space with properties not otherwise achievable by bulk, monolithic counterparts. Their superior specific strength, stiffness, and energy absorption, as well as their multi-functionality, makes them desirable for a wide range of applications. The objective of this paper is to compile and present a review of the open literature focusing on the energy absorption of periodic three-dimensional cellular materials. The review begins with the methodical cataloging of qualitative and quantitative elements from 100 papers in the available literature and then provides readers with a thorough overview of the state of this research field, discussing areas such as parent material(s), manufacturing methods, cell topologies, cross-section shapes for truss topologies, analysis methods, loading types, and test strain rates. Based on these collected data, areas of great and limited research are identified and future avenues of interest are suggested for the continued maturation and growth of this field, such as the development of a consistent naming and classification system for topologies; the creation of test standards considering additive manufacturing processes; further investigation of non-uniform and non-cylindrical struts on the performance of truss lattices; and further investigation into the performance of lattice materials under the impact of non-flat surfaces and projectiles. Finally, the numerical energy absorption (by mass and by volume) data of 76 papers are presented across multiple property selection charts, highlighting various materials, manufacturing methods, and topology groups. While there are noticeable differences at certain densities, the graphs show that the categorical differences within those groups have large overlap in terms of energy absorption performance and can be referenced to identify areas for further investigation and to help in the preliminary design process by researchers and industry professionals alike.

Metal and metal oxide nanostructured materials have been chemically and physically characterized and tested concerning methylene blue (MB) photoremoval and UV antibacterial activity against Escherichia coli and Staphylococcus aureus. In detail, silver nanoparticles and commercial BaTiO3 nanoparticles were modified to obtain nanocomposites through sonicated sol–gel TiO2 synthesis and the photodeposition of Ag nanoparticles, respectively. The characterization results of pristine nanomaterials and synthetized photocatalysts revealed significant differences in specific surface area (SSA), the presence of impurities in commercial Ag nanoparticles, an anatase phase with brookite traces for TiO2-based nanomaterials, and a mixed cubic–tetragonal phase for BaTiO3. Silver nanoparticles exhibited superior antibacterial activity at different dosages; however, they were inactive in the photoremoval of the dye. The silver–TiOx nanocomposite demonstrated an activity in the UV photodegradation of MB and UV inhibition of bacterial growth. Specifically, TiO2/AgNP (30–50 nm) reduced growth by 487.5 and 1.1 × 103 times for Escherichia coli and Staphylococcus aureus, respectively, at a dose of 500 μg/mL under UV irradiation.

Wire and arc additive manufacturing (WAAM), recognized for its capability to fabricate large-scale, complex parts, stands out due to its significant deposition rates and cost-effectiveness, positioning it as a forward-looking manufacturing method. In this research, we employed two welding currents to produce samples of 316 austenitic stainless steel utilizing the Cold Metal Transfer wire arc additive manufacturing process (CMT-WAAM). This study initially evaluated the maximum allowable arc travel speed (MAWFS) and the formation characteristics of the deposition bead, considering deposition currents that vary between 100 A and175 A in both CMT and CMT pulse(CMT+P) modes. Thereafter, the effect of the CMT+P mode arc on the microstructure evolution was analyzed using the EBSD technique. The findings indicate that the arc travel speed and deposition current significantly affect the deposition bead’s dimensions. Specifically, an increase in travel speed or a reduction in current results in reduced bead width and height. Moreover, the employment of the CMT+P arc mode led to a reduction in the average grain size in the mid-section of the sample fabricated by CMT arc and wire additive manufacturing, from 13.426 μm to 9.429 μm. Therefore, the components of 316 stainless steel produced through the CMT+P-WAAM method are considered fit for industrial applications.

In engineering practice, similar surface insulation measures are typically applied to different parts of mass concrete surfaces. However, this can lead to cracking at the edges of the concrete surface or the wastage of insulation materials. In comparison to flat surfaces, the edges of mass concrete structures dissipate heat more rapidly, leading to more pronounced stress concentration phenomena. Therefore, reinforced insulation measures are necessary. To reduce energy consumption and enhance overall insulation effectiveness, it is essential to study the specific insulation requirements of both the flat surfaces and edges of concrete separately and implement targeted surface insulation measures. Taking the bridge abutment planned for pouring in Nanjing City as the research object, this study established a finite element model to explore the effects of different ambient temperatures and different surface heat dissipation coefficients on the early-age temperature and stress fields of different parts of the abutment’s surface. Based on simulation results, reasonable heat dissipation coefficients that meet the requirements for crack prevention on both the structure’s plane and edges under different ambient temperatures were obtained. The results indicate that under the same conditions, the reasonable heat dissipation coefficient at the edges was smaller than that on the flat surfaces, indicating the need for stronger insulation measures at the edges. Finally, mathematical models correlating ambient temperature with reasonable heat dissipation coefficients for the structure’s plane and edges at these temperatures were established, with high data correlation and determination coefficients (R2) of 0.95 and 0.92. The mathematical models were validated, and the results from finite element calculations were found to be consistent with those from the mathematical models, validating the accuracy of the mathematical models. The conclusions drawn can provide references for the insulation of similar engineering concrete planes and edges.

In the realm of thermal interface materials (TIMs), high thermal conductivity and low density are key for effective thermal management and are particularly vital due to the growing compactness and lightweight nature of electronic devices. Efficient directional arrangement is a key control strategy to significantly improve thermal conductivity and comprehensive properties of thermal interface materials. In the present work, drawing inspiration from natural leaf and branch structures, a simple-to-implement approach for fabricating oriented thermal conductivity composites is introduced. Utilizing carbon fibers (CFs), known for their ultra-high thermal conductivity, as branches, this design ensures robust thermal conduction channels. Concurrently, boron nitride (BN) platelets, characterized by their substantial in-plane thermal conductivity, act as leaves. These components not only support the branches but also serve as junctions in the thermal conduction network. Remarkably, the composite achieves a thermal conductivity of 11.08 W/(m·K) with just an 11.1 wt% CF content and a 1.86 g/cm3 density. This study expands the methodologies for achieving highly oriented configurations of fibrous and flake materials, which provides a new design idea for preparing high-thermal conductivity and low-density thermal interface materials.

The basal plane dislocation (BPD) density is one of the most important defects affecting the application of SiC wafers. In this study, numerical simulations and corresponding experiments were conducted to investigate the influence of cooling processes, seed-bonding methods, and graphite crucible materials on the BPD density in an 8-inch N-type 4H-SiC single crystal grown by the physical vapor transport (PVT) method. The results showed that the BPD density could be effectively reduced by increasing the cooling rate, optimizing the seed-bonding method, and adopting a graphite crucible with a similar coefficient of thermal expansion as the SiC single crystal. The BPD density in the experiments showed that a high cooling rate reduced the BPD density from 4689 cm−2 to 2925 cm−2; optimization of the seed-bonding method decreased the BPD density to 1560 cm−2. The BPD density was further reduced to 704 cm−2 through the adoption of a graphite crucible with a smaller thermal expansion coefficient.

Laser-directed energy deposition (DED), a metal additive manufacturing method, is renowned for its role in repairing parts, particularly when replacement costs are prohibitive. Ensuring that repaired parts avoid residual stresses and deformation is crucial for maintaining functional integrity. This study conducts experimental and numerical analyses on trapezoidal shape repairs, validating both the thermal and mechanical models with experimental results. Additionally, the study presents a methodology for creating a toolpath applicable to both the DED process and Abaqus CAE software. The findings indicate that employing a pre-heating strategy can reduce residual stresses by over 70% compared to no pre-heating. However, pre-heating may not substantially reduce final distortion. Notably, final distortion can be significantly mitigated by pre-heating and subsequently cooling to higher temperatures, thereby reducing the cooling rate. These insights contribute to optimizing DED repair processes for enhanced part functionality and longevity.

Material shaping and joining are the two fundamental processes that lie at the core of many forms of metal manufacturing techniques, including additive manufacturing. Current metal additive manufacturing processes such as laser/e-beam powder bed fusion and Directed Energy Deposition predominantly use heat and subsequent melt–fusion and solidification to achieve shaping and joining. The energy efficiency of these processes is severely limited due to energy conversion losses before energy is delivered at the point of melt–fusion for shaping and joining, and due to losses through heat transfer to the surrounding environment. This manuscript demonstrates that by using the physical phenomenon of lowered yield stress of metals and enhanced diffusion in the presence of low amplitude high frequency oscillatory strain, metal shaping and joining can be performed in an energy-efficient way. The two performed simultaneously enable a metal additive manufacturing process, namely Resonance-Assisted Deposition (RAD), that has several unique capabilities, like the ability to print net-shape components from hard-to-weld alloys like Al6061 and the ability to print components with a very high aspect ratio. In this study, we show this process’s capabilities by printing solid components using aluminum-based metal alloys.

The development of a cost-effective and accurate model for predicting the fatigue life of materials is essential for designing thermal power plants and assessing their structural reliability under operational conditions. This paper reports a novel energy-based approach for developing unified models that predict the fatigue life of boiler tube materials in ultra-supercritical (USC) power plants. The proposed method combines the Masing behavior with a cyclic stress–strain relationship and existing stress-based or strain-based fatigue life prediction models. Notably, the developed models conform to the structure of the modified Morrow model, which incorporates material toughness (a temperature compensation parameter) into the Morrow model to account for the effects of temperature. A significant advantage of this approach is that it eliminates the need for tensile tests, which are otherwise essential for assessing material toughness in the modified Morrow model. Instead, all material constants in our models are derived solely from fatigue test results. We validate our models using fatigue data from three promising USC boiler tube materials—Super304H, TP310HCbN, and TP347H—and their welded joints at operating temperatures of 500, 600, and 700 °C. The results demonstrate that approximately 91% of the fatigue data for all six materials fall within a 2.5× scatter band of the model’s predictions, indicating a high level of accuracy and broad applicability across various USC boiler tube materials and their welded joints, which is equivalent to the performance of the modified Morrow model.

Magnesium (Mg)-matrix composites have excellent damping and electromagnetic shielding properties. However, the mismatch between their strength and toughness limits their wide application. The aim of this work is to overcome the strength-toughness mismatch by constructing micro- and nanostructures while maintaining the good functional properties of Mg-matrix composites. Electrophoretic deposition (EPD) was used to spread carbon nanotubes (CNTs) out evenly on a Mg foil matrix. After spark plasma sintering (SPS), the grain organisation was refined, and the interlayer bonding was strengthened by hot rolling deformation. Finally, the microstructure, mechanical properties, damping properties, and electromagnetic shielding properties of the composites were analysed. Compared with the pure Mg laminates, the tensile strength and elongation of the CNT/Mg laminates were increased by 6.4% and 108.4%, respectively, with the significant improvement in toughness resulting from the increase in energy required for crack propagation due to the laminate structure. When the total rolling deflection reaches 80%, the interlayer bond strength of the material is significantly increased, the grain is further refined, and the strength and elongation of the composite material reaches the optimum, with the tensile strength reaching 241.70 MPa and the elongation reaching 6.90%. The interlayer interface and grain refinement also affected the damping Mg and electromagnetic shielding effect of the composites. This work provides an experimental idea for the preparation of high-performance structure-function integrated Mg-based materials.

We investigated the electronic structure of Mg-, Si-, and Zn-doped four-faceted [001]- and [110]-oriented SnO2 nanowires using first-principles calculations based on the linear combination of atomic orbitals (LCAO) method. This approach, employing atomic-centered Gaussian-type functions as a basis set, was combined with hybrid density functional theory (DFT). Our results show qualitative agreement in predicting the formation of stable point defects due to atom substitutions on the surface of the SnO2 nanowire. Doping induces substantial atomic relaxation in the nanowires, changes in the covalency of the dopant–oxygen bond, and additional charge redistribution between the dopant and nanowire. Furthermore, our calculations reveal a narrowing of the band gap resulting from the emergence of midgap states induced by the incorporated defects. This study provides insights into the altered electronic properties caused by Mg, Si, and Zn doping, contributing to the further design of SnO2 nanowires for advanced electronic, optoelectronic, photovoltaic, and photocatalytic applications.

This study reported a multi–functional Co0.45Fe0.45Ni0.9–MOF/NF catalyst for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting, which was synthesized via a novel shape–preserving two–step hydrothermal method. The resulting bowknot flake structure on NF enhanced the exposure of active sites, fostering a superior electrocatalytic surface, and the synergistic effect between Co, Fe, and Ni enhanced the catalytic activity of the active site. In an alkaline environment, the catalyst exhibited impressive overpotentials of 244 mV and 287 mV at current densities of 50 mA cm−2 and 100 mA cm−2, respectively. Transitioning to a neutral environment, an overpotential of 505 mV at a current density of 10 mA cm−2 was achieved with the same catalyst, showing a superior property compared to similar catalysts. Furthermore, it was demonstrated that Co0.45Fe0.45Ni0.9–MOF/NF shows versatility as a bifunctional catalyst, excelling in both OER and HER, as well as overall water splitting. The innovative shape–preserving synthesis method presented in this study offers a facile method to develop an efficient electrocatalyst for OER under both alkaline and neutral conditions, which makes it a promising catalyst for hydrogen production by water splitting.

MXenes are a family of two-dimensional nanomaterials. Titanium carbide MXene (Ti3C2Tx-MXene), reported in 2011, is the first inorganic compound reported among the MXene family. In the present work, we report on the study of the composition and various physical properties of Ti3C2Tx-MXene nanomaterial, as well as their temperature evolution, to consider MXenes for space applications. X-ray diffraction, thermal analysis and mass spectroscopy measurements confirmed the structure and terminating groups of the MXene surface, revealing a predominant single OH layer character. The temperature dependence of the specific heat shows a Debye-like character in the measured range of 2 K–300 K with a linear part below 10 K, characteristic of conduction electrons of metallic materials. The electron density of states (DOS) calculations for Ti3C2OH-MXene reveal a significant DOS value at the Fermi level, with a large slope, confirming its metallic character, which is consistent with the experimental findings. The temperature dependence of electrical resistivity of the MXene samples was tested for a wide temperature range (3 K–350 K) and shows a decrease on lowering temperature with an upturn at low temperatures, where negative magnetoresistance is observed. The magnetoresistance versus field is approximately linear and increases its magnitude with decreasing temperature. The magnetization curves are straight lines with temperature-independent positive slopes, indicating Pauli paramagnetism due to conduction electrons.

Transition metal dichalcogenides (TMDs), particularly monolayer TMDs with direct bandgap properties, are key to advancing optoelectronic device technology. WSe2 stands out due to its adjustable carrier transport, making it a prime candidate for optoelectronic applications. This study explores monolayer WSe2 synthesis via H2-assisted CVD, focusing on how carrier gas flow rate affects WSe2 quality. A comprehensive characterization of monolayer WSe2 was conducted using OM (optical microscope), Raman spectroscopy, PL spectroscopy, AFM, SEM, XPS, HRTEM, and XRD. It was found that H2 incorporation and flow rate critically influence WSe2’s growth and structural integrity, with low flow rates favoring precursor concentration for product formation and high rates causing disintegration of existing structures. This research accentuates the significance of fine-tuning the carrier gas flow rate for optimizing monolayer WSe2 synthesis, offering insights for fabricating monolayer TMDs like WS2, MoSe2, and MoS2, and facilitating their broader integration into optoelectronic devices.

As a key guarantee and cornerstone of building quality, the importance of deformation prediction for deep foundation pits cannot be ignored. However, the deformation data of deep foundation pits have the characteristics of nonlinearity and instability, which will increase the difficulty of deformation prediction. In response to this characteristic and the difficulty of traditional deformation prediction methods to excavate the correlation between data of different time spans, the advantages of variational mode decomposition (VMD) in processing non-stationary series and a gated cycle unit (GRU) in processing complex time series data are considered. A predictive model combining particle swarm optimization (PSO), variational mode decomposition, and a gated cyclic unit is proposed. Firstly, the VMD optimized by the PSO algorithm was used to decompose the original data and obtain the Internet Message Format (IMF). Secondly, the GRU model optimized by PSO was used to predict each IMF. Finally, the predicted value of each component was summed with equal weight to obtain the final predicted value. The case study results show that the average absolute errors of the PSO-GRU prediction model on the original sequence, EMD decomposition, and VMD decomposition data are 0.502 mm, 0.462 mm, and 0.127 mm, respectively. Compared with the prediction mean square errors of the LSTM, GRU, and PSO-LSTM prediction models, the PSO-GRU on the PTB0 data of VMD decomposition decreased by 62.76%, 75.99%, and 53.14%, respectively. The PTB04 data decreased by 70%, 85.17%, and 69.36%, respectively. In addition, compared to the PSO-LSTM model, it decreased by 8.57% in terms of the model time. When the prediction step size increased from three stages to five stages, the mean errors of the four prediction models on the original data, EMD decomposed data, and VMD decomposed data increased by 28.17%, 3.44%, and 14.24%, respectively. The data decomposed by VMD are more conducive to model prediction and can effectively improve the accuracy of model prediction. An increase in the prediction step size will reduce the accuracy of the deformation prediction. The PSO-VMD-GRU model constructed has the advantages of reliable accuracy and a wide application range, and can effectively guide the construction of foundation pit engineering.

Cementitious composites are ubiquitous in construction, and more and more research is focused on improving mechanical properties and environmental effects. However, the jury is still out on which material can achieve low-carbon and high-performance cementitious composites. This article compares the mechanical and environmental performance of zero-dimensional fullerenes, one-dimensional carbon nanotubes (CNTs), two-dimensional graphene oxide (GO), and three-dimensional nano-graphite platelets (NGPs) on cementitious composites. The literature review shows that two-dimensional (2D) GO has the best mechanical and environmental performance, followed by 3D NGPs, 1D CNTs, and 0D fullerenes. Specifically, GO stands out for its lower energy consumption (120–140 MJ/kg) and CO2 emissions (0.17 kg/kg). When the optimal dosage (0.01–0.05 wt%) of GO is selected, due to its high specific surface area and strong adhesion to the matrix, the compressive strength of the cementitious composites is improved by nearly 50%. This study will help engineers and researchers better utilize carbon-based nanomaterials and provide guidance and direction for future research in related fields.

Since the implementation of the Materials Genome Project by the Obama administration in the United States, the development of various computational materials’ databases has fundamentally expanded the choice of industries such as materials and energy. In the field of thermoelectric materials, the thermoelectric figure of merit (ZT) quantifies the performance of the material. From the viewpoint of calculations for vast materials, the ZT values are not easily obtained due to their computational complexity. Here, we show how to build a database of thermoelectric materials based on first-principle calculations for the electronic and heat transport of materials. Firstly, the initial structures are classified according to the values of bandgap and other basic properties using the clustering algorithm K-means in machine learning, and high-throughput first principle calculations are carried out for narrow-bandgap semiconductors which exhibit a potential thermoelectric application. The present framework of calculations mainly includes a deformation potential module, an electrical transport performance module, a mechanical and a thermodynamic properties module. We have also set up a search webpage for the calculated database of thermoelectric materials, providing search facilities and the ability to view the related physical properties of materials. Our work may inspire the construction of more computational databases of first-principle thermoelectric materials and accelerate research progress in the field of thermoelectrics.

Normally, the acidic impurities in hemihydrate phosphogypsum (HPG) must be neutralized when HPG is utilized, and a little amount of calcium hydroxide (CH) is the best choice. In this paper, the effects of excessive CH (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.% of HPG) for carbonation curing on the performance of hardened HPG paste were studied. According to the results of macro tests and microanalyses of XRD, TG, SEM-EDS, MIP and N2 physisorption, it could be verified that CaF2, Ca3(PO4)2 and a large amount of nanoscale CaCO3 crystals were produced as a result of neutralization and carbonation, and the compressive strength and the water resistance of carbonated HPG + CH paste were significantly improved due to the effects of nanoscale CaCO3 crystals on pore refinement and the coverage on the surfaces of gypsum crystals of the hardened paste. Therefore, this study suggests a feasible and green method for recycling HPG/PG, with the collaborative effects of neutralization, performance enhancement and reductions in CO2 emissions.

To reduce drying shrinkage of AASC mortar (AASM), mixed aggregate mixed with river sand (RS) and silica sand in three sizes was used to investigate the effect of the physical properties of mixed aggregate on shrinkage reduction. A mixture of river sand (0.2–0.8 mm), S1 (2.5–5.0 mm), S2 (1.6–2.5 mm), and S3 (1.21–160 mm) had river sand–silica sand mean diameter ratios (dr) of 7.68 (S1/RS), 3.75 (S2/RS), and 3.02 (S3/RS). The compressive strength and drying shrinkage characteristics of mixed aggregates according to fineness modulus, surface area, bulk density, and pore space were investigated. It had the highest bulk density and lowest porosity at a substitution ratio of 50%, but the highest strength was measured at a substitution ratio of 50% or less. High mechanical properties were shown when the fineness modulus of the mixed aggregate was in the range of 2.25–3.75 and the surface area was in the range of 2.25–4.25 m2/kg. As the substitution rate of silica sand increased, drying shrinkage decreased. In particular, the drying shrinkage of RS + S1 mixed aggregate mixed with S1 silica sand, which had the largest particle size, was the smallest. When silica sand or river sand was used alone, the drying shrinkage of the sample manufactured only with S1, which has the largest particle size of silica sand, was the smallest among all mixes. Compared to RS, at a 5% activator concentration, drying shrinkage was reduced by approximately 40% for S1, 27% for S2, and 19% for S3. At a 10% concentration, S1 showed a reduction effect of 39%, S2 by 28%, and S3 by 13%. As a result of this study, it was confirmed that the drying shrinkage of AASM could be reduced simply by controlling the physical properties of the aggregate mixed with two types of aggregate. This is believed to have a synergistic effect in reducing drying shrinkage when combined with various reduction methods published in previous studies on AASM shrinkage reduction. However, additional research is needed to analyze the correlation and influencing factors between the strength, pore structure, and drying shrinkage of AASM using mixed aggregate.