Production Of Materials Research Articles

STATE AND PROSPECTS OF THE DEVELOPMENT OF UKRAINE'S BUILDING INDUSTRY IN THE CONDITIONS OF THE ECONOMIC CRISIS CAUSED BY THE FULL-SCALE AGGRESSION OF THE RUSSIA, FROM THE POINT OF VIEW OF ECONOMIC CYCLICITY

The article is dedicated to examining the specific manifestations of economic cyclicality in Ukraine's building materials industry under martial law conditions. The analysis reveals that the full-scale war has led to the destruction of approximately 20% of enterprises, while others have experienced significant declines in production volumes, market access, raw material sources, and human resources. The features of war-induced economic crises are compared with cyclical overproduction crises, showing that military actions immediately push the economy into a recession phase. However, recovery may commence even before the end of hostilities due to the economy reaching the trough of the economic cycle.The article explores various approaches to defining and understanding the concept of "economic crisis," highlighting the importance of identifying its causes and characteristics. Key factors influencing the transition between different phases of economic cycles—recession, depression, recovery, and expansion—are identified. It is noted that the moments of phase transition are critical to economic development, as they represent the shift from quantitative changes in one phase to qualitative changes in the next.The dynamics of real estate prices are analyzed as one of the key indicators signaling the onset of the recovery phase. Additionally, the article formulates the components of a development strategy for Ukraine’s construction sector during the recovery period, taking into account the consequences of the war. These components include the localization of building materials production, improving housing comfort, ensuring the environmental sustainability of building materials, conserving resources in their production (particularly energy), involving foreign aid in the reconstruction process, and recycling demolition waste into building materials. It is determined that the future development of the construction industry must also address the issue of effectively insulating protective structures and bomb shelters with eco-friendly materials, necessitating further development of domestic building materials that meet the urgent demands of wartime. The article concludes with the prospect of utilizing hemp-lime building materials in the reconstruction process, as they fully align with the proposed development strategy

Eco‐efficiency improvement strategies for disinfectants

AbstractDisinfectants are essential products for reducing health risks, but they also have significant environmental impacts. This study assessed the Eco‐efficiency of disinfectants based on the NBR ISO 14045:2014. Primary data were collected from Brazilian producers, while secondary data were obtained from patents and the Ecoinvent database. The system boundaries encompassed cradle‐to‐consumer use. The selling price was adopted as the product system value indicator (economic analysis). Raw materials production had the greatest impact on the environmental performance of disinfectants A (Antibacterial, surfactant and preservative) and C (Antibacterial, surfactant and opacifier). Disinfectant B, in addition to raw materials production (Antibacterial, opacifier and surfactant), also experienced significant impacts from consumer transport. These critical processes represent more than 60% of the overall impacts in both categories. The Eco‐efficiency matrix (profile) related environmental and economic indicators. All disinfectants occupied quadrants three or four, indicating high impact on the environmental categories. Disinfectant C had the highest Eco‐efficiency while disinfectant B had the lowest, mainly due to its product system value. Sensitivity analysis indicated environmentally viable changes in the products' composition, such as replacing the antibacterial, surfactant, preservative, and opacifier. Energy and water consumption did not significantly impact the assessed products.

Integrated systems for the production of food, energy and materials as a sustainable strategy for decarbonization and land use: The case of sugarcane in Brazil

The projected escalating use of renewables to meet the Paris Agreement goals has raised concerns about land-use pressures, particularly from biomass-based systems. This study introduces the concept of Integrated Food, Energy, and Materials Systems (IFEMS) as a strategy to optimize land-use efficiency for decarbonization. To evaluate the land-use efficiency of IFEMS and other renewable resource-based systems, a novel parameter termed decarbonization density (DD) is proposed, which aggregates all services that reduce GHG emissions and remove carbon from atmosphere per unit of land. A case study on an archetypical integral sugarcane utilization system in Brazil is analyzed, indicating that the simultaneous production of food, energy, and materials can synergistically aid decarbonization efforts. The estimated DD for the baseline scenario is 20 tCO2e/ha, while in the innovative scenario (SC-innov), it rises to 145 tCO2e/ha. Most of this increase stems from including the production of fermented meat as a substitute of beef, which accounts for three quarters of DD's value in SC-innov, indicating a high potential of this technology for contributing to decarbonization. These findings suggest that IFEMS may represent a land-use strategy at least as efficient as other renewable energy systems, with the potential to grow as biomass conversion technology advances into more complex systems. However, these advances also pose the challenge of integrating diverse product streams for different markets, which will likely require the coordination of multiple stakeholders within an industrial ecosystem rather than a single-actor model.

Fracture behavior of 3D-printed thermoplastics—A dilemma of fracture toughness versus fracture energy

The Material Extrusion (ME) technique in 3D printing facilitates the production of thermoplastic materials with diverse cellular or lattice-like infill geometries, enabling the creation of lightweight, high-performance materials. This study investigates the influence of infill geometry and relative density on the fracture behavior of 3D-printed thermoplastics produced through ME. Polylactic acid (PLA) is used as the model material, with unit cell geometries-square, triangle, and Kagome-and relative densities ranging from 0.4 to 0.8 explored. Tensile tests are first conducted to determine in-plane elastic moduli in two orthogonal directions, accounting for unit cell anisotropy. These results are employed in effective fracture energy calculations. Compact tension fracture tests follow, quantitatively characterize crack growth characteristics in both directions. In both tests, digital image correlation method is used to measure full field strain distributions. Three significant findings emerge. First, there is a power scaling relationship between Elastic Modulus and relative density across all unit cells, with Kagome exhibiting the highest correlation constant. Triangle and Kagome unit cells show negligible orthotropic responses in perpendicular directions for varying relative densities. Second, the relationship between nondimensional fracture toughness and relative density follows a similar scaling law, with minor variations depending on unit cell type. The correlation factor slightly dependens on unit cell geometry but remains around 3 across the the examined relative density range. Third, considering the dissipation of inelastic fracture energy, both triangle and Kagome unit cell geometries demonstrate an order of magnitude higher effective fracture energy (i.e., crack growth resistance) compared to the square unit cell. This is associated with toughening mechanisms such as crack deflection and bifurcation. These findings highlight the disparity between fracture toughness and effective fracture energy in assessing the fracture resistance of 3D-printed thermoplastics, clearly demonstrating that fracture toughness alone is insufficient for a comprehensive assessment. The proposed scaling laws provide predictive insights into the fracture toughness of polymeric materials produced via the ME method.

Innovative assessment of reactivity in fly ash: The role of particle size distribution characteristics

The relationship between the intrinsic properties of seven different types of fly ash and the compressive strength of the resulting geopolymers was investigated. A comprehensive examination of the effect of chemical and mineralogical compositions, particle size distribution, on the compressive strength of the fly ash-based geopolymers were performed. Results revealed that particle size distribution had a more significant impact on reaction activity than amorphous phase content or average particle size alone. Therefore, a novel concept of 'reaction volume' based on the geopolymerization reaction mechanism was proposed, which reveals a high correlation between the reactivity of fly ash and the compressive strength of geopolymers, thereby enhancing the predictability of the process. The degree of reactivity, formulated through the integration of reaction volume and amorphous silica-aluminum content, was identified as a robust predictor of compressive strength, which can serve as a crucial tool for evaluating fly ash for the production of alkali-activated materials.

Investigating durability potentials of selected kaolin clays in Edo state, south–south region of Nigeria

The production of cementious material as a result of inorganic binders (geopolymer) being produced from aluminosilicate involving synthesized reaction with strong alkali solutions such as sodium silicates admixture by a poly-condensation reaction (geopolymerisation) between alumina and silica materials had greatly contributed to its use as alternative material and reduction in overdependence of Portland cement in Nigeria. The study aimed at the importance of reducing pressure on mining of non-renewable clay by concentrating on the qualities and grades of geopolymer produced using kaolin clays from Afor-okpella, Aforwa, Ossiomo and Ugbine kaolin clays in Edo state after subjecting each of them to optimal calcination process parameter (temperature): Afor-okpella: 600 °C,700 °C,800 °C,Aforwa: 600 °C,700 °C,800 °C, Ossiomo: 600 °C, 700 °C, 800 °C and Ugbine:600 °C, 700 °C,800 °C for which nearly complete dehydroxylation of the material and the durability properties the local material (kaolin clays) from Edo State geopolymer concrete will exhibit than normal concrete. By grounding Edo kaolin clays used, sieved to 212 μm and calcined at a temperature of 600 °C, 700 °C and 800 °C for six (6) hours. The geopolymers were synthesized using sodium silicate was (Na2SiO3) as the activating solution. The setting time, compressive strength (for 7 and 28 days), bulk density, water absorption capacity and apparent porosity test at the 28 day of curing was determined. The results for compressive strength of synthesized geopolymers for 7 days of curing were between 10.0N/mm2 to 19.0 N/mm2 and 13.8 N/mm2 to 25.6 N/mm2 for 28 days of curing high enough to be a useful Portland cement alternative. Meanwhile, the results of water absorption capacity was as low as 10.0% for 28 days of curing.Comparing the values with ASTM standards C6918-12, C216, C902 and C90 confirmed their suitability and durability for use as geopolymer materials and applicability to making geopolymer bricks and load bearing concrete masonry units.

Organic acid-fractionated lignin silver nanoparticles: Antimicrobial, anticancer, and antioxidant characteristics

Bioactive substances are utilized to treat a variety of diseases. Green lignin-mediated silver nanoparticles (L-Ag-NPs) have significant promise as a building block in the production of bio-renovation materials. The work optimized organic acid extraction to remove lignin from residual fermented hybrid Napier grass byproducts. We subsequently produced L-Ag-NPs. FTIR, XRD, DLS, and STEM characterized the sample. L-Ag-NPs were tested for antioxidant activity with the DPPH, DMPD, FRAP, and ABTS assays, as well as antibacterial activities. Antimicrobial activity was evaluated using four pathogenic bacteria (Klebsiella pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli). In contrast, cytotoxicity and ROS production assays were carried out using the HeLa cell line. The findings showed that L-Ag-NPs had high antioxidant efficiency. For each bacteria isolate, the antimicrobial activity showed favorable growth inhibition, with significant variations in L-Ag-NPs. L-Ag-NPs were reported to have an IC50 of 43.61 g/mL in the cytotoxicity test, and a significant increase in ROS generation was seen. In conclusion, L-Ag NPs have an excellent prospect in the pharmaceutical and biomedical industries and can be a dependable and environmentally safe material for their potential use.

Сharacteristics of demolition waste management in the regions of Ukraine

The volume of waste left from war-related destruction amounts to 10-12 million tons per year. Such volume is comparable to the annual volume of municipal solid waste generated in Ukraine. This situation led to formation of unauthorized landfills and complicated the existing problem of industrial, consumer, construction and demolition waste management. Consequently, the issue of destruction waste management became a pressing environmental and socio-economic problem. The objective of this research is to assess the characteristics of destruction waste management in the regions of Ukraine. Destruction waste is generated during construction of new buildings and public structures, as well as during renovation or demolition of existing buildings and structures; including general-use facilities. It is estimated that, before the war, nearly 7 million tons of construction and demolition waste was generated annually, with more than 50% being transported to municipal solid waste landfills. Specialized landfills for its disposal were virtually non-existent in the regions of Ukraine, so this waste, despite its resource value, was taken to municipal solid waste landfills or unauthorized dumps. Some components of construction and demolition waste are toxic. Destruction waste includes parts (fragments) of damaged (destroyed) objects, as well as materials and items that were inside or next to such objects at the time of damage (destruction) and/or during disassembly activities, including those that fully or partially lost their consumer properties and cannot be reused at the place of their origin or discovery. Destruction waste pollutes the environment, so one of the ways to reduce environmental risks is to develop an effective waste management system to stop chaotic processes during disassembly activities. Destruction waste differs from construction and demolition waste by the presence of accompanying hazardous components, complicating the development of a waste management system. The main components of destruction waste should be used as secondary raw materials for construction, production of building materials and other purposes. Provided that appropriate physical-geographic, engineering-geological, hydrogeological, technical, and socio-economic conditions are available, it is advisable to create temporary waste storage sites, with their subsequent use as secondary raw materials in the post-war period for restoration of civil, industrial, and transport infrastructure in the regions of Ukraine.

Production and characterization of nano-magnetic material through different red mud reduction processes

Red mud (RM), is an industrial waste deriving from the production of primary aluminium, with about 200 Mtons generated annually. In this work, the reduction of RM for obtaining magnetic products with particular chemical-physical characteristics has been explored. RM reduction was carried out in a semi-closed reducing environment at a high processing temperature (750–1100 °C) in the presence of carbon-rich ash (CA) resulting from a commercial pyro-gasification plant and by using an H2 atmosphere. All the materials were characterized by elemental analysis, XRD diffraction technique, SEM/EDX microscopy, thermogravimetry and infrared spectroscopy. The materials obtained under the different conditions have in common the presence of small iron-magnetic domains (with different iron oxidation states), in the order of hundreds of nanometres, and by the ferro-magnetic or paramagnetic response to an external magnetic field. In particular, the material pre-treated with HCl (enriched in iron) and reduced with H2 showed very good magnetic responses, more iron in reduced oxidative states showing high ferro-magnetic responses to the external field. The synthesised materials are quite differents each others and appear to have several potential fields of application, as sorbents for specific wastewater pollutants, as materials for CO2 capture, for catalysis and (bio)sensing applications. Nevertheless, the high interconnection between the magnetic and non-magnetic phases limit the direct separation or the iron enrichment. Further efforts should be focused on the functional studies and subsequent LCA and LCC analyses.

PSXII-8 Environmental cost effects of different manure treatment methods on dairy farms

Abstract The issue of manure disposal in dairy farms has long been a significant challenge afflicting the dairy farming industry, as manure poses various detrimental effects such as greenhouse gas emissions and land pollution. This remains an urgent concern for the industry to address. The traditional tank fermentation oxidation pond form of manure treatment and the new biogas power generation mode of manure treatment are currently widely employed in dairy farming enterprises. The evaluation and analysis of the environmental cost of new treatment modes should be conducted using scientific methods to determine which approach is more environmentally friendly. We selected two dairy farms with roughly the same number of dairy cows and the same management level, and the feed formula of the two dairy farms was basically consistent with the herd structure. Among them, the traditional tank fermentation manure treatment pasture, and the biogas power generation pasture. The Life Cycle Assessment (LCA) method of SimaPro software was used, and the software version was 9.0.0.48. In the life cycle assessment, we take into account the depletion of fossil energy, cement, metals, chemical products, electricity, heat, and mechanical pumps during the process of manure treatment. After accounting, the following conclusions are developed. During the whole life cycle of dairy farming, greenhouse gas emissions mainly fall into three types: methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). CH4 accounts for 64% of the total emissions, which is mainly produced in the process of animal feeding, and a small part comes from manure treatment. CO2 accounts for 34% of the total emissions from the production of feed raw materials. The smallest proportion of transport and fossil energy consumption is N2O, which is mainly produced by manure treatment processes and accounts for 2% of total emissions. The environmental cost of the traditional tank fermentation oxidation pond is 17.6% greater than that of the new type of biogas power generation.

A Review of Carbon Anode Materials for Sodium-Ion Batteries: Key Materials, Sodium-Storage Mechanisms, Applications, and Large-Scale Design Principles.

Sodium-ion batteries (SIBs) have been proposed as a potential substitute for commercial lithium-ion batteries due to their excellent storage performance and cost-effectiveness. However, due to the substantial radius of sodium ions, there is an urgent need to develop anode materials with exemplary electrochemical characteristics, thereby enabling the fabrication of sodium-ion batteries with high energy density and rapid dynamics. Carbon materials are highly valued in the energy-storage field due to their diverse structures, low cost, and high reliability. This review comprehensively summarizes the typical structure; energy-storage mechanisms; and current development status of various carbon-based anode materials for SIBs, such as hard carbon, soft carbon, graphite, graphene, carbon nanotubes (CNTs), and porous carbon materials. This review also provides an overview of the current status and future development of related companies for sodium-ion batteries. Furthermore, it offers a summary and outlook on the challenges and opportunities associated with the design principles and large-scale production of carbon materials with high-energy-density requirements. This review offers an avenue for exploring outstanding improvement strategies for carbon materials, which can provide guidance for future application and research.

Developing Enhanced SiTiOC/PS/TiO2 hybrid aerogels with excellent mechanical properties and ultra-low thermal conductivity

Ceramic aerogels exhibit an extremely high porosity, low weight, and exceptionally low thermal conductivity, making them suitable as insulating materials for use in challenging environments. The widespread application of conventional ceramic aerogels is typically constrained by the fragile nature of the material and its high-temperature infrared radiation transparency. Here, we successfully prepared SiTiOC/PS/TiO2 hybrid aerogels by effectively synthesizing them using polyvinyl alcohol (PVA) as the carbon skeleton and reinforcing them with polystyrene microspheres (PS) and PAN nanofibers loaded with TiO2 (TiO2/PAN NFs), and TiO2/PAN NFs as shading material. This was achieved through a combination of the polymer precursor transformation method, sol-gel method, and techniques such as freeze-drying and electrostatic spinning. The findings indicated that the fabricated SiTiOC/PS/TiO2 hybrid aerogels exhibited a lightweight structure, exceptionally high infrared reflectivity, remarkably low thermal conductivity, and outstanding mechanical characteristics. The successful synthesis of the SiTiOC/PS/TiO2 hybrid aerogels offers a novel approach for advancing the production of various thermal insulation materials.

Microwave-assisted in-situ synthesis of low-dimensional perovskites within metal-organic frameworks for optoelectronic applications

Halide perovskites are renowned for their remarkable optoelectronic properties, yet their application is hindered by stability challenges. Metal-organic frameworks (MOFs) have emerged as promising matrices for enhancing perovskite durability. In this study, we achieved the in-situ synthesis of a series of perovskites within the MOF-5 matrix, spanning three-dimensional, quasi two-dimensional, and two-dimensional structures, via microwave-assisted reaction techniques. This microwave synthesis method has proven to be a rapid and efficient approach for the high-yield production of perovskite materials. These MOF-5⊃perovskites exhibited superior optical properties, positioning them as promising candidates for various optoelectronic applications, including white light-emitting diodes and optical wireless communication (OWC) systems. Significantly, our perovskites demonstrated high and consistent communication rates, making them suitable for both space and underwater OWC deployments. Overall, our study underscores the potential of microwave-assisted synthesis in advancing high-performance perovskite materials, offering valuable insights for the development of future optoelectronic devices.

A review of thermochromic materials for coating applications: production, protection, and degradation of organic thermochromic materials

A review of thermochromic materials for coating applications: production, protection, and degradation of organic thermochromic materials

Rational design of short-chain dehydrogenase/reductase for enantio-complementary synthesis of chiral 1,2-diols by successive hydroxymethylation and reduction of aldehydes.

Enantiopure 1,2-diols are widely used in the production of pharmaceuticals, cosmetics, and functional materials as essential building blocks or bioactive compounds. Nevertheless, developing a mild, efficient and environmentally friendly biocatalytic route for manufacturing enantiopure 1,2-diols from simple substrate remains a challenge. Here, we designed and realized a step-wise biocatalytic cascade to access chiral 1,2-diols starting from aromatic aldehyde and formaldehyde enabled by a newly mined benzaldehyde lyase from Sphingobium sp. combined with a pair of tailored-made short-chain dehydrogenase/reductase from Pseudomonas monteilii (PmSDR-MuR and PmSDR-MuS) capable of producing (R)- and (S)-1-phenylethane-1,2-diol with 99% ee. The planned biocatalytic cascade could synthesize a series of enantiopure 1,2-diols with a broad scope (16 samples), excellent conversions (94%-99%), and outstanding enantioselectivity (up to 99% ee), making it an effective technique for producing chiral 1,2-diols in a more environmentally friendly and sustainable manner.

Strategic incentives and natural capital accounting for sustainable supply chain management: Measuring reputational impacts and consumers’ perceptions of the use of water through behavioural experimental studies

Within a sustainable supply chain management approach, this study investigates strategic issues that can either favour or impede the implementation of natural capital accounting. Among other things, the originality of such consists of the joint consideration of sustainability, operational, and reputational issues, forging the link between measuring the use of natural resources and preserving companies' intangible capital. More specifically, through two scenario-based behavioural experiments with a total sample of 252 consumers in the UK, we analyse how information regarding the use of water (i.e., water footprint) affects firms' reputation (i.e., trust, attitude towards the firm, word-of-mouth, brand avoidance). We also investigate consumers' perceptions when companies seek to (1) increase the transparency of their consumption of natural capital (i.e., a conceptual proxy for the adoption of natural capital accounting) and (2) rationalize this consumption (i.e., a goal aligned with the objectives of natural capital accounting). The method employed is adequate as it allows the detection and measurement of respondents' perceptions of specific issues presented in the different scenarios. The choice of the UK as the setting reflects the importance of the country in the fashion industry, as it has a solid consumer base and is home to several international fashion brands. The supply chain management scope refers to the link between water consumption (which often takes place in the production of raw materials (e.g., cotton) and in transformation processes (e.g., fabric dyeing, tanning) by suppliers), fashion brands' reputation, and consumers' perceptions, with the joint consideration of these four phases sustaining the delimitation. Building on the premises of the resource-based view and signalling theory, the study is contextualized in the fashion industry as its current production levels require a significant consumption of natural resources, particularly water. Results show that, while the publication of the water footprint may damage companies’ reputations, initiatives aimed at increasing transparency and reducing environmental impact can reverse these losses to a large extent. In this sense, the study advances the idea that, despite possibly presenting undesirable consequences at first, the adoption of natural capital accounting can be beneficial to firms later on, with reputational gains representing important strategic incentives. Further research in different countries and industries will be beneficial to assess the possible context impact on our results.

Opportunities and Challenges in the Application of Bioplastics: Perspectives from Formulation, Processing, and Performance.

Tremendously negative effects have been generated in recent decades by the continuously increasing production of conventional plastics and the inadequate management of their waste products. This demands the production of materials within a circular economy, easy to recycle and to biodegrade, minimizing the environmental impact and increasing cost competitiveness. Bioplastics represent a sustainable alternative in this scenario. However, the replacement of plastics must be addressed considering several aspects along their lifecycle, from bioplastic processing to the final application of the product. In this review, the effects of using different additives, biomass sources, and processing techniques on the mechanical and thermal behavior, as well as on the biodegradability, of bioplastics is discussed. The importance of using bioplasticizers is highlighted, besides studying the role of surfactants, compatibilizers, cross-linkers, coupling agents, and chain extenders. Cellulose, lignin, starch, chitosan, and composites are analyzed as part of the non-synthetic bioplastics considered. Throughout the study, the emphasis is on the use of well-established manufacturing processes, such as extrusion, injection, compression, or blow molding, since these are the ones that satisfy the quality, productivity, and cost requirements for large-scale industrial production. Particular attention is also given to fused deposition modeling, since this additive manufacturing technique is nowadays not only used for making prototypes, but it is being integrated into the development of parts for a wide variety of biomedical and industrial applications. Finally, recyclability and the commercial requirements for bioplastics are discussed, and some future perspectives and challenges for the development of bio-based plastics are discussed, with the conclusion that technological innovations, economic incentives, and policy changes could be coupled with individually driven solutions to mitigate the negative environmental impacts associated with conventional plastics.

Reactive formation of C3N4 as a by-product of AISI 1070 parts produced by laser powder bed fusion in N2 atmosphere

AbstractIn metal additive manufacturing (AM), inert gases are traditionally used to achieve a controlled atmosphere and mitigate the effects of residual reactive gases. However, the interaction between gases and laser processes, particularly in reactive laser powder bed fusion (RL-PBF) technology, offers the possibility of opening up new avenues for material synthesis. In this experimental work, the authors observed the presence of C3N4 in the residual powder during the manufacture of AISI 1070 steel parts by L-PBF, indicating a reactive process occurred during parts production. This investigation revealed the formation in the working chamber of a waste product containing C3N4 carbon nitride, due to the reaction between the carbon released from the steel and the nitrogen in the chamber. Remarkably, despite carbon depletion, the final product of AISI 1070 steel complies with the specifications of use. Hence, the L-PBF machine was modified to allow black powder sampling from various locations in the chamber. Authors attempted to enhance the production of the C3N4 material by increasing the SED up to 7143 J/mm2 to sublimate a pure graphite rod and concurrently manufacture parts in AISI 1070, in a nitrogen atmosphere. The results obtained at higher SED values showed that in both cases (graphite rod or AISI 1070 steel) a C3N4 compound in the black powder is formed in the investigated atmosphere by reaction of nitrogen atoms with the carbon atoms vaporized by the laser beam. Thus, the study highlights the novel achievement of synthesizing carbon nitride as a high-value by-product while producing functional AISI 1070 steel parts via L-PBF through reaction with nitrogen atmosphere.

Improvement of the negative-temperature properties of calcium sulphoaluminate cement by three multifunctional chemical admixtures

The construction of concrete in cold climates is associated with a significant energy consumption and an extensive carbon footprint. This is attributed to the production of raw materials and the necessity for additional measures to prevent frost damage. Finding suitable and environmental-friendly cementitious materials and admixtures for cold weather is a relatively straightforward and cost-effective solution. In this study, calcium sulphoaluminate cement (CSA) was selected, and low doses of three admixtures (lithium carbonate (Li2CO3), calcium mitrite (Ca(NO2)2), and calcium chloride (CaCl2)) were used at low dosages to modify the properties of CSA at sub-zero temperatures. The results showed that: The addition of Li2CO3 to CSA can significantly increase the early hydration of CSA, improve the early mechanical properties, shorten the curing time, and significantly reduce the content of frozen water in the pores. Ca(NO2)2 ensured the sustained late-stage development of CSA strength, which reached 90.5 MPa at −7+28 d; CaCl2 significantly lowered the freezing point of the cement paste and also improved the mid and late-stage strength.

Residues from the Oil Pressing Process as a Substrate for the Production of Alternative Biochar Materials

The purpose of this study was to evaluate the feasibility of using residues from cooking oil production to produce alternative biochar fuels along with optimizing the pyrolysis process. The work consisted of carrying out the pyrolysis process at varying temperatures and holding times at the final temperature, and then evaluating the energy potential of the materials studied. Taking into account aspects of environmental emissions, the content of selected oxides in the flue gases generated during the combustion of cakes and the biochar obtained from them was evaluated. Plant biomass derived from a variety of oilseeds, i.e., fennel flower (Nigella sativa L.), rapeseed (Brassica napus L. var. Napus), flax (Linum usitatissimum L.), evening primrose (Oenothera biennis L.), milk thistle (Silybum marianum L. Gaertn.) and hemp (Cannabis sativa L.), was used to produce biochar. The experimental data have shown that the obtained biochar can have a calorific value of nearly 27 MJ kg−1. The use of pyrolysis allowed for a maximum increase in the calorific value of nearly 41% compared to non-thermally processed cakes and a several-fold decrease in carbon monoxide, nitrogen oxides and sulfur dioxide emissions. According to these results, it can be concluded that the pyrolysis process can be an attractive method for using residues from the production of various cooking oils to produce alternative biofuels, developing the potential of the circular economy.