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This study explores a novel method for fabricating Ca-α-sialon ceramics using a calcium aluminate oxide eutectic additive. Conventional sintering techniques for Ca-α-sialon ceramics employ nitrogen-containing additives to facilitate the Si–N bond substitution mechanism with Al–O and Al–N bonds. In this work, calcium aluminate additives are utilized, leading to the formation of Ca-α-sialon ceramics via carbothermal reduction processes and partial nitridation of aluminum oxide. The influence of varying calcium aluminate content (5, 10, 15, 30, and 40 wt%) on the phase composition of Ca-α-sialon ceramics, produced by hot pressing at 1650 °C in a nitrogen atmosphere, was investigated. Results indicate that increasing the calcium aluminate content leads to the formation of a β-sialon phase, which subsequently transforms into Ca-α-sialon. At 40 wt% calcium aluminate, complete conversion of α-Si 3 N 4 to Ca-α-sialon is achieved, with significant glassy phase formation at the grain boundaries. The study elucidates the relationship between calcium aluminate content, phase composition, lattice parameters, mechanical properties, oxidation resistance, and thermal expansion of the ceramics. [ABSTRACT FROM AUTHOR]

Calcium oxide (CaO) which originated from calcium aluminate cement (CAC, binder) in alumina-magnesia refractory castables significantly deteriorates its high-temperature properties, particularly corrosion resistance. Hence, the development trend of castables is moving towards ultra-low cement and even cement-free castables. In the present work, the influence of different binders, including aluminate cement and alumina-silica gel bonding, on microstructural evolution, thermal-mechanical properties, and corrosion resistance of Al 2 O 3 -MgO castables has been investigated. The obtained results indicated the hot strength of the Al 2 O 3 -MgO cement castables was much higher than that of Al 2 O 3 -MgO castables with gel-bonding. While the latter possessed a better residual strength (9.1 MPa) and residual strength ratio (59.71 %) after thermal-shock testing when compared to the cement bonding sample (6.73 MPa, 50.12 %). Compared to the CACs-bonded samples, slag penetration resistance displayed a notable enhancement in the gel bonding sample. A typical corrosion mechanism based on FactSage® (Version 8.1) thermodynamic simulation was proposed to elucidate the corrosion behavior. [ABSTRACT FROM AUTHOR]

Synthetic textiles such as polyesters are essential for daily life. However, large‐scale production generates large amounts of waste. This study introduces a new approach for valorising polyester textile waste (PTW) by transforming it into a catalyst for biodiesel production via pyrolysis. Specifically, a metal/carbon composite (PTW + steel slag [SS] composite—PSC) with enhanced catalytic properties was prepared by pyrolysing PTW with SS. The alkaline metals in SS facilitate the carbonisation of PTW via decarboxylation, resulting in a PSC rich in carbon, iron, and alkaline compounds. This composite featured mesopores that were larger than the micropores (MPs) typically found in PTW char. The use of porous material (silica) in thermally induced transesterification has been proven to be an efficient method for biodiesel production, achieving a yield of 97.20 wt.% in 1 min (faster than the 93.82 wt.% yields in 60 min observed from conventional alkali‐catalysed transesterification). However, the high reaction temperature (≥ 360°C) poses economic/technical challenges. To overcome this, PSC has been employed as a catalyst in thermally induced transesterification, leveraging its mesoporous structure and high alkaline content, particularly calcium oxide. The PSC achieved a biodiesel yield of 98.10 wt.% at a markedly lower reaction temperature of 120°C within 1 min. This performance was not attainable using silica or PTW char under similar conversion conditions. These findings highlight the potential of PSC produced through the pyrolysis of PTW and SS as effective catalysts for biodiesel production. This process is a promising strategy for converting waste into valuable resources and mitigating the environmental impacts associated with polyester waste. [ABSTRACT FROM AUTHOR]

Hydrothermal degradation deteriorates the fracture toughness and strength of tetragonal stabilised zirconia. The phase transformation to the monoclinic phase is particularly critical for materials with lower stabiliser content such as 2 mol% and 3 mol% yttria stabilised zirconia (2YSZ and 3YSZ). In this work, two routes in two-step sintering and co-doping with calcium oxide are analysed to mitigate the degradation. Both strategies show a reduction in average grain size of the 2YSZ while maintaining a comparable densification. The achieved smaller grains suppress the hydrothermal degradation rates. In addition, a mitigating effect beyond the reduction in grain size of YSZ is found for CaO doping. 1.6 mol% CaO co-doped 2YSZ shows less than 4% of monoclinic phase after 50 h in an autoclave with H 2 O at 134 °C. Pure 2YSZ contrarily reaches 100% monoclinic phase after 20 h at the same conditions. A suppression of degradation by CaO doping was also observed for the composite of nickel oxide and 3 mol% yttria stabilised zirconia. Hence, CaO co-doping can be an interesting strategy to increase resistivity against hydrothermal degradation for both biomedical and renewable energy applications. The findings further outline a route to achieve tetragonal YSZ with lower yttria contents than 2 mol%. • Two approaches were analysed to mitigate hydrothermal degradation in 2YSZ and 3YSZ. • Co-doping with CaO and two-step sintering reduced the grain growth and degradation. • CaO co-doping mitigated the degradation beyond the effect of the grain size. • A complete suppression of degradation was achieved by the addition of 1.6 mol% CaO. • The results show a route to ageing-resistant tetragonal YSZ with lower yttria contents. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of the partial replacement of natural hydraulic lime (NHL) with waste glass powder (GP) on the physical, mechanical, and microstructural properties of NHL mortars. In the experimental study, five mixtures containing up to 50% GP were prepared to evaluate its effect on the flow, carbonation, unit weight, water absorption, porosity, ultrasonic pulse velocity, capillary water absorption, compressive strength, and microstructure of NHL mortars. The experimental results suggest that the partial replacement of NHL with GP significantly affects the properties of NHL mortars. A reduction in compressive strength was observed with increasing GP content in mortars at both early and later stages. Nevertheless, the compressive strength difference between samples containing 50% GP and the reference was found to be relatively minor at 91 days, implying an enhanced pozzolanic reaction over time. The incorporation of GP improved the consistency and capillary water absorption of mortars, while the opposite was observed for ultrasonic pulse velocity, porosity, and water absorption. The microstructural analysis revealed distinct changes in the structure of samples incorporating GP. The partial substitution of hydraulic lime with GP could be beneficial in reducing the CO2 emissions of NHL mortars. [ABSTRACT FROM AUTHOR]

Reducing energy consumption in the building sector has driven the search for more sustainable construction methods. This study explores the potential of cork-modified mortars reinforced with basalt fabric, focusing on optimizing both mechanical and hygroscopic properties. Six mortar mixtures were produced using a breathable structural mortar made from pure natural hydraulic lime, incorporating varying percentages (0–3%) of cork granules (Quercus suber) as lightweight aggregates. Micro-computed tomography was first used to assess the homogeneity of the mixtures, followed by flow tests to evaluate workability. The mixtures were then tested for water absorption, compressive strength, and adhesion to tuff and clay brick surfaces. Adhesion was measured through pull-off tests, to evaluate internal bonding strength. Additionally, this study examined the relationship between surface roughness and bond strength in FRLM composites, revealing that rougher surfaces significantly improved adhesion to clay and tuff bricks. These findings suggest that cork-reinforced mortars offer promising potential for sustainable construction, achieving improved hygroscopic performance, sufficient mechanical strength, internal bonding, and optimized surface adhesion. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol (PVA) and chitosan (CS) were mixed with purple tomato anthocyanins (PTA), and then nano zinc oxide (nano-ZnO) or calcium chloride (CaCl2) were added to prepare PVA/CS/PTA/ nano-ZnO (PCP-ZnO) or PVA/CS/PTA/CaCl2 (PCP-CaCl2) films. The effects of nano-ZnO and CaCl2 on the morphology, pH response, color stability, color reversibility, antibacterial activity, antioxidant activity, mechanical properties, water vapor permeability and UV absorption characteristics of films were studied. In addition, its application in intelligent packaging to monitor the freshness of pork was also studied. It was found that both nano-ZnO and CaCl2 can reduce the transmittance of the film in the visible light region, and the film with addition of nano-ZnO was more sensitive to pH. During the 14 day storage period, the film modified with CaCl2 exhibited better color stability. SEM images indicate that the addition of nano-ZnO or CaCl2 alters the microstructure of the film. The mechanical, antibacterial and antioxidant properties and also the application as freshness indicator of PCP-CaCl2 film were superior to those of PCP-ZnO film. Those indicated that the prepared PCP-CaCl2 film is a potential candidate for active and intelligent packaging applications. [ABSTRACT FROM AUTHOR]

The global focus is directed towards extensive ingestion and bioaccumulation of plastic additives and organic dyes such as Tetrabromobisphenol A (TBBPA) and Auramine-O (AO). However, their recalcitrant properties make them toxic chemicals and require an efficient removal strategy based on waste-derived semiconductor nanocomposite. The present study involves the structural configuration of NiFe 2 O 4 created through green methods, integrated into waste shell CaO to create the NiFe 2 O 4 @CaO (NFC) nanocomposite. P-XRD verified the crystalline catalyst, while microscopic examination unveiled spherical NiFe 2 O 4 particles decorating the irregular surface of CaO. The green NFC nanocomposite exhibited superior degradation efficiency for TBBPA (92 %) and AO (95 %) compared to the individual CaO and NiFe 2 O 4 nanoparticles under conditions of minimal pollutant concentration (10 mg L−1), utilizing a catalyst load of 30 mg at neutral pH under natural Sunlight. 1st-order reaction kinetics following early Langmuir adsorption and degradation at optimum conditions. Involvement of •OH, O 2 −•, and holes in the photocatalysis mechanism suggested that hydroxyl radicals significantly contributed to breaking complex molecules of TBBPA and AO, as revealed in Scavenger analysis. The removal of real water samples was also analyzed. The release of TBPPA from underwater, which has toy materials and electric wire materials, was investigated at various time intervals, along with the evaluation of the degradation of the leached TBBPA. Also, NFC has exhibited exceptional sustainability, retaining its usefulness over nine cycles without significant action decreases. In conclusion, the environmentally welcoming NFC is a cost-effective composite for industries and wastewater pollutants removal with good surface properties. [ABSTRACT FROM AUTHOR]

This study investigated the potential of incorporating crushed brick powders (CBPs) and hydrated lime (HL) as additives in concrete production. Various tests were conducted on mortar, paste, and concrete samples to evaluate the performance of different blend types. The results reveal that among 3%, 6%, 9%, and 12% HL additive in the cement-CBP blend, 6% HL addition yields a significant increase in compressive strength of up to 16% compared to the control mortar. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) indicate improved hydration and reduced calcium hydroxide content in CBP-blended pastes, particularly in the blend with 6% HL. The concrete blend incorporating crushed bricks (C-CB) with 6% HL (C-CB-6HL) demonstrates superior early strength gain, surpassing the control blend by approximately 2.1% at 28 days and exhibiting the highest compressive strength at 90 days. It also shows enhanced moisture resistance, with a reduction in water absorption percentage of up to 10.6% compared to the control blend, reduced water permeability, improved resistance against chloride permeability, and better durability against acid attack compared to other blends. Overall, the C-CB-6HL blend shows the most promising durability characteristics, highlighting the potential for sustainable concrete production. Its outcomes have implications for shaping technical standards and promoting sustainable practices in the construction industry, aligning with environmental conservation goals. [ABSTRACT FROM AUTHOR]

The effect of different filler types on the properties of asphalt mortar before and after water saturation was studied by laboratory tests. Under both dry and water-saturated circumstances, four alternative fillers, limestone powder, hydrated lime, PO42.5 cement, and brake pad powder, are used, evaluated, and compared. The study methodology included characterizing the micromorphology, while X-ray diffraction imaging analysis and scanning electron microscopy were used to determine the chemical composition of the asphalt mortar following water saturation. To quantify the effects of moisture on the bonding mechanisms, surface energy concepts were employed to compute the surface free energy parameters of the asphalt mortar made with different filler materials. Dynamic shear rheometry was employed in the investigation to describe the rheological characteristics of the asphalt mortar as a function of filler under different water saturation conditions. The bonding strength of the asphalt mortars with various fillers was then quantitatively measured using pullout tests to account for the coupling effects of moisture and temperature. The findings of the laboratory tests generally showed that the asphalt mortar's effectiveness declined following moisture conditioning and saturation in water. However, hydrated lime, brake pad powder, and cement showed promise in strengthening the bonding of fillers and asphalt, with hydrated lime being superior. Likewise, the asphalt mortar's ability to tolerate moisture and resist water damage was also generally improved by hydrated lime. [ABSTRACT FROM AUTHOR]

In this study, the bulk modification method via incorporating two different types of waterproof admixtures was adopted to make natural hydraulic lime-based mortars more durable. The influence of two admixtures and their dosages on the hydration, physical, mechanical, and aggressive environment resistance properties were evaluated. The correlations between pore and water absorption characteristics, between hydration, pore characteristics, and mechanical strength were interpreted. Results showed that two waterproof admixtures changed the microscopic reaction between different components as well as internal structure of NHL-based mortar. Introduction of silane impregnant improved the workability of natural hydraulic lime-based mortars, and the appropriate dosage of silane impregnant facilitated hydration and improved mechanical strength at 28 and 90 days. Silane impregnant modified mortars were no more hydrophilic, acid resistance was improved while water absorption characteristics were not obviously improved even resulting in degraded freeze-thaw cycle resistance. Introduction of silicon-acrylic latex deteriorated the workability and retarded hydration of natural hydraulic lime-based mortars, regardless of dosage, leading to the degradation of mechanical strength. However, water absorption characteristics and freeze-thaw cycle and acid resistance can get a noticeable improvement when appropriate dosage was adopted. [ABSTRACT FROM AUTHOR]

Background: Chicken eggshells, a common poultry byproduct, are rich in calcium and provide a sustainable source for producing calcium oxide nanoparticles (CaO NPs). Their use in eco-friendly synthesis aligns with the growing emphasis on sustainable materials for environmental and biomedical applications. Objectives: This study develops an eco-friendly method for synthesizing CaO NPs from chicken eggshells, characterizes their physicochemical properties, and evaluates their antibacterial and antifungal activities. It also tests their effectiveness in removing heavy metal ions (Pb2+, Cr2+, Cd2+, and Hg2+) from aqueous solutions. Methods: CaO NPs were synthesized by calcining chicken eggshells at 700°C for 7 h. Comprehensive characterization included analysis of crystalline structure, morphology, optical properties, bandgap energy, chemical composition, and thermal stability. Antibacterial and antifungal activities were tested using the wellagar diffusion method. Batch adsorption experiments evaluated heavy metal ion removal under varying conditions of pH, temperature, stirring time, and adsorbent concentration Results: The synthesis produced spherical, single-crystal CaO NPs with diameters ranging from 5 to 30 nm and a crystalline size of approximately 20 nm. The nanoparticles had a bandgap energy of about 4.7 eV. Significant antibacterial activity was observed against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli, with increasing inhibition zones correlating with nanoparticle concentration. The CaO NPs also effectively inhibited Candida albicans. For efficient metal ion removal, the optimal conditions were found to be 30 min at pH 6 with 40 mg of CaO NPs at 25°C, achieving recovery rates of 98% for Pb2+, 97% for Cd2+, 97% for Cr2+, and 97% for Hg2+. For near-complete removal, extending the process to 70 min at pH 6 with 40 mg of CaO NPs at 45°C achieved the highest recovery rates: 99% for Pb2+, 98% for Cd2+, 99% for Cr2+, and 99% for Hg2+, though this approach involves higher energy and cost. Conclusion: CaO NPs derived from chicken eggshells are effective antibacterial agents and adsorbents for heavy metal removal. These findings highlight their potential for sustainable applications in environmental and biomedical fields. [ABSTRACT FROM AUTHOR]

In the present investigation, process parameters were optimized in order to enhance the reduction of calcium oxide (CaO) from sugarcane molasses using acid centrifugation treatment. To predict the effects of process factors on CaO reduction efficiency, a response surface approach with a central composite design was selected. The polynomial quadratic equation was used to predict CaO removal efficiency, and the analysis of variance (ANOVA) test was utilized to assess the relevance of process factors. The appropriateness of the developed model was determined by regression analysis, which yielded a higher R‐squared value of 0.99334 ± 0.01. At the optimum process parameters of 100°C temperature, 50°Bx, and 3.50 pH, the CaO clarification efficacy of 66.17 wt.% was achieved. The experimental results indicated that for acidic centrifugation treatment, the experimentally observed CaO reduction of 65.94 wt% is in close agreement with the model equation's predicted maximum CaO reduction of 66.17 wt% with a t‐test value of 0.497726. Under such conditions, 0.982 wt.% CaO sugarcane molasses was obtained, which is low when compared to the world average of 1.5% CaO content of sugarcane molasses. Furthermore, the implementation of an artificial neural network (ANN) provided a better prediction model for CaO reduction, with a substantial R‐squared value of 0.99866. However, the genetic algorithm (GA) optimization resulted in an actual CaO reduction of 66.21 wt.% with a t‐test value of 0.497726. [ABSTRACT FROM AUTHOR]

The deterioration of sintering bed permeability is an important factor that hinders thick‐bed sintering. Flux is one of the key factors that determines the bonding degree of quasiparticles. Selecting high‐quality flux is an effective way to improve both the permeability and thickness of the sintering bed. Herein, the hydration activity of quicklime flux is used as a criterion to assess quality. Two types of quicklimes with different activity levels are selected for comparative analysis in three aspects: microstructure, sinter quasiparticle granulation performance, and the sinter mineralization process. The experimental results show that active quicklime has a higher CaO content and fewer impurities. The small and dense CaO particles give active quicklime significant advantages in raw material granulation and sinter mineral formation. The application of active quicklime can effectively improve the permeability of the sintering bed; notably, the drying fines’ removal rate decreases from 22.81% to 2.42% with an increase in the ratio of active quicklime addition. However, this affects the average particle size of quasiparticles. To address this issue, solutions are determined by adjusting the condition parameters. It is concluded that active quicklime plays an important role in enhancing the permeability of the sintering bed during thick‐bed sintering production. [ABSTRACT FROM AUTHOR]

Granulated micro-fine limes have recently been introduced as liming materials which are purportedly more effective than conventional agricultural limes in terms of rapidly correcting subsoil acidity in no-tillage systems. Hydrated limes are known to react more quickly in soils than calcitic limes, yet their soil permeability has not been evaluated under Mediterranean climate growing conditions. Therefore, the aim of this controlled study was to compare soil permeation and pH neutralization of different liming materials (hydrated lime, calcitic agricultural lime, micro-fine lime and molasses-granulated micro-fine lime) in two contrasting (sand and sandy loam) acid (pHKCl < 4.1) topsoils under simulated Mediterranean climate conditions. Limes were surface applied to 40 cm soil columns and then rainfall (350 mm) was simulated. Subsequently, soil chemical properties (pH, exchangeable cations, available P) were measured in 5 cm increments. Application of all liming materials increased soil pH 1–2 pH units above target pHKCl of 5.5 in the top 5 cm of both soils. Only hydrated lime was able to increase soil pHKCl (5.7–6.8) below 5 cm up to a depth of 15 cm on the sand soil. Hydrated lime, however, resulted in substantial over-liming (pHKCl 7.3–8.7) of the top 5 cm of soil compared to the other materials. Granulated micro-fine lime reacted more slowly than the agricultural limes and is therefore not a suitable quick-fix for subsoil acidity in rain-fed no-till systems under Mediterranean climate rainfall conditions. Whereas hydrated lime showed potential in ameliorating subsoil acidity in the sand soil within one season of rainfall. [ABSTRACT FROM AUTHOR]

This study aims to investigate the relationship between digital printing colour performance and the raw materials used in a matt glaze. Inkjet technology has enhanced the decorative properties of ceramic tiles in production. Improving the colour perception of the glaze is possible by optimizing the raw materials in the glaze, which results in less ink usage and thus lower costs. Investigation of the colour performance of glazes is possible by determining the L* a* b* values of the colours as well as the gamut colour volumes. Colour of the samples were evaluated by spectrophotometer and i1 profiler. Gamut volume was calculated by 3D CIE chromaticity diagrams of ICC profiles. It was observed that the colour saturation was higher in the samples where the pigment was homogeneously distributed in the glaze microstructure. SiO 2 particles not embedded in the glass structure observed in the glaze microstructure disrupt the colour intensity. The low sphere temperature value of the composition made with wollastonite enabled the SiO 2 particles to be embedded in the glaze. When wollastonite was used instead of dolomite as the source of calcium oxide in mat glaze, the colour gamut volume reached its highest value (11262), consequently increasing colour saturation. Conversely, the lowest colour gamut volume (6475) was obtained when dolomite was used instead of wollastonite. [ABSTRACT FROM AUTHOR]

AbstractEggshell waste has proved to be one of the most valuable natural sources due to its considerable contributions to several research fields. Herein, calcium oxide derived from various kinds of eggshell wastes has been introduced using the calcination method at different temperatures. The prepared micro- or nano-particles of calcium oxide are also characterized by XRD, FE-SEM, TEM, BET, and FT-IR techniques to clarify their morphological and structural aspects completely. With mild basicity, this bio-derived catalyst has been applied to the green synthesis of chalcones via the Claisen − Schmidt condensation reaction. Ultimately, the reusability of the catalyst is examined to increase the catalyst economization. [ABSTRACT FROM AUTHOR]

Amongst the many types of food waste, eggshells contain various minerals and bioactive materials, and they can become hazardous if not properly disposed of. However, they can be made useful for the environment and people by being converted to environmentally friendly catalytic materials or environmental purification agents. Simple calcination can enhance their properties and thereby render them suitable for catalytic and environmental applications. This work aimed to prepare CaO from waste eggshells and examine its effectiveness in photocatalytic pollution remediation, electrocatalytic activity, optical sensing, and antibacterial activities. As opposed to other techniques, this calcination process does not require any chemical reagents due to the high purity of CaCO3 in eggshells. Calcium oxide nanoparticles were prepared by subjecting waste eggshells (ES) to high-temperature calcination, and the synthesized CaO nanoparticles were characterized for their structural, morphological, chemical, optical, and other properties. Furthermore, their photocatalytic degradation of methylene blue dye and antibacterial efficiency against Escherichia coli and Staphylococcus aureus were investigated. It was found that the green-converted CaO can be efficiently used in environmental applications, showing good catalytic properties. [ABSTRACT FROM AUTHOR]

Materials for the conservation of cultural heritage must meet specific demands, such as high durability, service life, and compatibility with other materials used in the original building structures. Due to their low permeability to water and water vapor and their high rigidity, the use of Portland cement (PC) mortars, despite their high mechanical resistance and durability, does not represent an appropriate solution for the repair of historic masonry and structures. Their incompatibility with the original materials used in the past, often on a lime basis, is therefore a serious deficiency for their application. On the other hand, lime-based mortars, compared to PC-based materials, are more susceptible to mechanical stress, but they possess high porosity, a high water vapor transmission rate, and moderate liquid water transport. This study aims at the development of two types of lime-based mortars, calcium lime (CL) and hydraulic lime (HL). The modification of mortars was conducted with a carbon-based nanoadditive and graphene nanoplatelets (GNs) in three dosages: 0.1%, 0.3%, and 0.5% of the binder weight. The enhancement of CL mortars by GNs greatly increased mechanical strength and affected heat transport characteristics, while other characteristics such as porosity, water absorption, and drying rate remained almost similar. The application of GNs to HL not only enhanced the strength of mortars but also decreased their porosity, influenced pore size distribution, and other dependent characteristics. It can be concluded that the use of graphene nanoplatelets as an additive of lime-based composites can be considered a promising method to reinforce and functionalize these composite materials. The improved mechanical resistance while maintaining other properties may be favorable in view of the increasing requirements of building materials and may prolong the life span of building constructions. [ABSTRACT FROM AUTHOR]

The increasing incidence of heat stress due to global climate change poses a significant challenge to avocado (Persea americana) cultivation, particularly in regions with intense solar radiation. This review evaluates sun protection strategies, focusing on the efficacy of different sunscreen products such as kaolin, titanium dioxide, and calcium oxide in mitigating thermal stress in avocado trees. The application of these materials was shown to reduce leaf and fruit surface temperatures, improve photosynthetic efficiency, and enhance fruit quality by preventing sunburn and dehydration. Despite these benefits, challenges remain, including the optimal timing and dosage of application, and the potential residue impacts on fruit marketability. The review emphasizes the need for ongoing research to develop more effective formulations and to integrate these sun protection strategies with other agronomic practices. The role of extension services in educating producers about the proper use of these technologies is also highlighted as crucial for the successful adoption of sun protection measures in avocado farming. [ABSTRACT FROM AUTHOR]

Green processes for synthesizing nanocomposites are a hot area of research today as traditional processes are expensive, inefficient, harmful for synthesizing organic and inorganic molecules, and unsuitable for large-scale operations. The present study investigates the capacity of green synthesized Calcium oxide nanoparticles (CaO NPs) for efficiently removing Rhodamine B. Chemical reduction was replaced with Mulberry (Morus nigera) leaf extract as an environmentally friendly reaction mechanism. CaO NPs are characterized by various analytical techniques including EDX, BET, SEM, FTIR, TGA, Zeta Potential, Point of Zero Charge (PZC), and XRD. Maximum adsorption of Rhodamine B by CaO NPs is revealed at an initial concentration of Rhodamine B of 80 ppm, a temperature of 343 K, and contact time of 60 min, 0.4 g of adsorbent at a pH value of 7. Maximum removal of Rhodamine B by CaO NPs was found to be 98.2% which is promising with this small amount of adsorbent (0.4 g). Diverse Kinetic and adsorption isotherms are employed in this study to determine the requirement and significance of the adsorption process. Various adsorption isotherms such as Freundlich, Temkin, Dubinin–Radushkevich (D–R), and Langmuir models have been employed. Among the kinetic adsorption isotherms Elovich, Intraparticle kinetic model, pseudo 1st order, and pseudo 2nd order models were applied. The current study investigates the thorough understanding of the Rhodamine B adsorption process including the mechanism of adsorption using condition optimization, characterization, and model applications. The proposed adsorbent can be employed for the green removal of Rhodamine B from wastewater of industry with maximum efficiency and favorable regeneration properties. [ABSTRACT FROM AUTHOR]

This study examines limestone properties and calcination process to enhance product quality. Limestone burning produces lime (CaO, calcium oxide) and carbon dioxide (CO2). Lime is a substance highly reactive and turns into slaked lime (Ca(OH)2, calcium hydroxide) when exposed to water. Six limestone samples from Tuscan Nappe sedimentary sequence, outcropping in the Monti d'Oltre Serchio area (NW Tuscany, Italy), were selected and calcined at different temperatures (800, 900, 1000 and 1100 °C). The obtained lime was slaked, and chemical, mineralogical and petrographic analyses were conducted to study its reactivity during slaking process. Key factors influencing lime reactivity were identified: calcination temperature/time and limestone characteristics (chemical and mineralogical composition). The lime reactivity was measured through the rate of lime hydration reaction. Results showed that higher reactivity in lime, lower calcination temperature. The increase in temperature and time leads to an increase of CaO grain size and, consequently, to a decrease in reactivity. Temperature increase has a more significant effect on the increasing of grain size and reactivity than time. The optimal calcination temperature was found to be 900 °C, like that of ancient limekilns. The study emphasized the close link between lime reactivity and chemistry/mineralogy of limestone. Overall, the research provides insights for improving limestone calcination processes and obtaining superior products. [ABSTRACT FROM AUTHOR]

The clean and efficient utilization of coal is a promising way to achieve carbon neutrality. Coking coal is a scarce resource and an important raw material in the steel industry. However, the presence of pyrite sulfur affects its clean utilization. Nonetheless, this pyrite could be removed using depressants during flotation. Commonly used organic depressants (sodium lignosulfonate (SL), calcium lignosulfonate (CL), and pyrogallol (PY)) and inorganic depressants (calcium oxide (CaO) and calcium hypochlorite (Ca(ClO)2)) were chosen in this study. Their inhibition mechanism was discussed using FTIR, XPS, and molecular dynamics (MD) methods. The desulfurization ability of organic depressants was shown to be better than inorganic ones. Among the organic depressants, PY proved to be advantageous in terms of low dosage. Physical adsorption was identified as the main interaction form of SL, CL, and PY onto the surface of pyrite, as evidenced from FTIR and XPS analyses. Similarly, MD simulation results showed that hydrogen bonds played a proactive role in the interactions between PY and pyrite. The diffusion coefficient of water molecules on the pyrite surface was also observed to decrease when organic depressants were present, indicating an increase in the hydrophilicity of pyrite. This research is of great significance to utilize sulfur-containing coal and minerals. [ABSTRACT FROM AUTHOR]

Phosphogypsum is a common industrial solid waste that faces the challenges of high stockpiling and low utilization rates. This study focuses on the mechanical properties and internal characteristics of cementitious materials with a high phosphogypsum content. Specifically, we examined the effects of varying amounts of ground granulated blast furnace slag (5–28%), fly ash (5–20%), and hydrated lime (0.5–2%) on the stress–strain curve, unconfined uniaxial compressive strength, and elastic modulus (E50) of these materials. The test results indicate that increasing the ground granulated blast furnace slag content can significantly enhance the mechanical properties of phosphogypsum-based cementitious materials. Additionally, increasing the fly ash content can have a similar beneficial effect with an appropriate amount of hydrated lime. Furthermore, microscopic analysis of the cementitious materials using a scanning electron microscope revealed that the high sulfate content in phosphogypsum leads to the formation of calcium aluminate as the main product. Concurrently, a continuous reaction of the raw materials contributes to the strength development of the cementitious materials over time. The results could provide a novel method for improving the reusing phosphogypsum amount in civil engineering materials. [ABSTRACT FROM AUTHOR]

Ultra‐high‐performance cementitious composite (UHPCC) incurs higher economic costs and resource wastage due to its high cement/silica fume (SF) content. The paper aims to achieve sustainability and environmental friendliness of UHPCC by substituting cement/SF with glass powder (GP). The influence of various GP particle sizes and substitution levels on the mechanical properties of UHPCC was investigated. X‐ray diffraction and scanning electron microscopy were employed to analyze the impact of GP on the hydration process of UHPCC from a microscopic perspective. In addition, the internal damage pattern of GP‐UHPCC was simulated by the RFPA3D program. The results show that the addition of GP could achieve superior fluidity than GP‐0. Compared to conventional UHPCC, GP‐20 exhibits improved strength, initial flexural toughness, and residual flexural toughness. Furthermore, finer GP particle sizes contribute to enhanced matrix strength and flexural energy absorption capacity to some extent. Additionally, the incorporation of 5%–20% GP leads to an increase in the characteristic peaks of hydrated lime and C‐S‐H gel, which are beneficial to improving the internal microstructure of the matrix. Based on the RFPA3D program, the crack area, principal stress distribution, and acoustic emission energy of specimens with 15%–25% GP substitution levels were significantly higher than those of specimens with low substitution levels (0%–10%). Generally speaking, a GP substitution level of 15%–25% is found the most effective range for improving strength, and toughness behavior in this study. [ABSTRACT FROM AUTHOR]

In the present work, medical waste ash was used as an aluminosilicate precursor to produce a geopolymer binder with stabilised heavy metals. The ash was initially calcined at a temperature of 800 °C for two hours to reduce the organic content. Calcined kaolin and medical waste ash were used as precursors to produce the geopolymer binder and sodium silicate and calcium oxides were used as alkaline activators. The effect of curing temperature (23, 60, and 100 °C) and the calcium oxide addition (0, 5, and 10%) on the geopolymer properties were evaluated. Eighteen geopolymer samples were prepared and evaluated for immobilizing heavy metals through the Toxicity Characteristic Leaching Procedure (TCLP). When compared to raw materials, TCLP results indicated that geopolymerization can significantly reduce the concentration of heavy metals in the medical waste ash leachate. The metal fixation percentages of the geopolymers ranged from 70 to 100%. The sequential extraction test results showed that geopolymerization (stabilization/solidification) is very beneficial in reducing the bioavailable fraction in the solid waste and maximizing the difficulty of fraction extraction. [ABSTRACT FROM AUTHOR]

This research explores the potential of use of waste scaling deposition from electric geysers (EGWS) to synthesize calcium oxide and address fluoride and nitrate contamination in water. The study adopts a circular economy framework by utilizing the synthesized calcium oxide to modify corn cob biochar through ball‐milling, creating a cost‐effective and environmentally sustainable adsorbent. The adsorbent is characterized and pHpzc analysis of CaO@CBC indicates sustained high adsorption capacities for nitrate and fluoride across a broad pH range (2–11). The adsorption kinetics follow a pseudo‐second‐order model, indicating chemisorption mechanisms. The Langmuir isotherm model fits well, showing high maximum adsorption capacities of 18.36 mg g−1 for fluoride and 19.27 mg g−1 for nitrate, surpassing those reported for other materials. Thermodynamic studies indicate that the uptake reactions of fluoride and nitrate are spontaneous and exothermic. Results from pH studies, XPS analysis, and FTIR offer insights into the adsorption mechanism by suggesting electrostatic attraction, inner‐sphere complexation, and ion exchange. The research establishes the efficacy of CaO‐impregnated biochar derived from electric geyser waste in removing fluoride and nitrate, offering a sustainable solution for water pollution. This work breakthroughs the development of efficient and eco‐friendly adsorbents for water treatment, aligning with the principles of a circular economy. [ABSTRACT FROM AUTHOR]

After the chelation and solidification of municipal solid waste incineration fly ash, there are still certain environmental hazards. Landfilling will occupy a large amount of land, and reusing can alleviate the pressure on landfill site. This article used alkali activation technology to prepare chelated fly ash mineral powder based alkali-activated cementitious material. In addition to exploring the feasibility of alkali-activated chelated fly ash, the influence of calcium oxide content on improving the performance of cementitious material was also explored. The results show that the compressive strength of solidified body is highest when calcium oxide content is 4% (mass fraction), while the compressive strength of solidified body slowly decreases when calcium oxide content exceedes 4%. The addition of calcium oxide promotes the formation of hydration products of C-S-H gel and significantly improves the compressive strength of material. Meanwhile, through leaching tests, it is found that the heavy metal leaching concentration of solidified body doped with calcium oxide is lower than that of solidified body without calcium oxide, and meets the limit values specified in "Standard for pollution control on the landfill site of municipal solid waste" (GB 16889-2008). [ABSTRACT FROM AUTHOR]

The debonding behavior of graphene / graphene oxide on calcium silicate hydrate substrate directly affects the performance of gelling composites, however it is difficult to achieve the debonding effect in traditional experiments. In order to clarify the debonding characteristics of graphene / graphene oxide, the debonding behavior of graphene / graphene oxide on calcium silicate hydrate substrate at nanoscale by molecular dynamics method was studied. The results show that the bonding properties of graphene / graphene oxide decrease with the increase of temperature, compared with graphene, the change of temperature has a greater effect on the bonding properties of graphene oxide. Among graphene oxide, epoxy-based graphene oxide is least affected by the change of temperature. The main factors affecting the bonding properties are the van der Waals forces and Coulomb interactions between graphene / graphene oxide and calcium silicate hydrate. High concentration and functional groups at the edge can significantly enhance bonding properties, and the effect of different functional groups on enhancing bonding properties is carboxyl group, hydroxyl group and epoxy group. [ABSTRACT FROM AUTHOR]

The deposition of Yellow River sediment in the middle and lower reaches is a significant factor in the siltation of reservoirs and the occurrence of serious flooding along the river. The efficient and valuable utilization of Yellow River sediment has already become a key research topic in this field. In this study, we have employed Yellow River sediment as the primary material, in conjunction with commercially available slag, fly ash, and quicklime as the binder, to develop a novel type of artificial flood-prevention stone. Following a 28-day standard curing procedure, the highest compressive strength of the prepared artificial stone was recorded at 4.29 MPa, with a value exceeding 0.7 MPa under wet conditions. The results demonstrated that the prepared artificial stone met the specifications for artificial flood-prevention stones. The curing mechanism, as evidenced by analyses from SEM and XRD testing, indicated that the alkali excitation process in the binder, which produced C-A-S-H gel, was the key factor in enhancing the compressive strength of the specimens. Notably, an evaluation of the amount of CO2 emissions and the cost of the artificial stone concluded that the preparation process was both environmentally friendly and cost-effective. [ABSTRACT FROM AUTHOR]

Rotary hearth furnaces and rotary kilns are the mainstream methods for large-scale treatment of electric furnace dust (EAFD) in steel companies, but they require a large amount of energy and have low product quality. The roasting conversion–separation technology uses calcium oxide to promote the conversion of zinc–iron spinel in EAFD into zinc oxide and dicalcium ferrite, but adding calcium oxide additionally increases production costs. Converter sludge (OGS) is rich in iron oxides and valuable components such as CaO, CaCO3, ZnFe2O4, etc. The free calcium oxide and calcium carbonate can be used as substitutes for pure calcium oxide. This paper designed a multi-solid waste collaborative reduction roasting process to realize the recovery of zinc and iron elements from OGS and EAFD and explore the feasibility of industrial treatment in rotary hearth furnace. The results show that harmful OGS can be used as the calcium agent in the roasting process. The calcium carbonate in OGS not only improves the conversion of iron oxide into metallic iron, but the decomposed CaO can promote the conversion of zinc–iron spinel in OGS and improve the dezincification effect. Better conditions are: 60% OGS, nC/nO = 1.2, roasting temperature 1150°C, roasting for 25 min; zinc content in the reduction product is 0.21%, and metallization rate is 78.53%, which can be used as a high-quality substitute or coolant for scrap steel raw materials in the steelmaking process. This process can realize green and comprehensive utilization of EAFD and OGS and is expected to achieve industrialization. [ABSTRACT FROM AUTHOR]

This study is devoted to the synthesis of aerated concrete by a non-autoclave method using ash from thermal power plants and a nanopreparation. Fullerenol-m was used as a nanopreparation. The fullerenol-m content in the sealing water of aerated concrete changed in the range of 0.00 ÷ 0.03 mas.%. The main performance characteristics of the nanostructured aerated concrete were studied, namely the compressive strength, impact toughness, thermal conductivity, density and moisture content. A significant improvement in the performance characteristics of the nanomodified aerated concrete compared to unmodified samples was demonstrated, which was most clearly manifested as an increase in impact toughness by several (three to five) times. The best performance characteristics of the modified aerated concrete were observed at a fullerenol-m concentration relative to the added cement within 0.022–0.028 wt.%. The authors attribute such a strong change and improvement in the physical, chemical and operational properties of aerated concrete when modified with fullerenol-m to the fact that fullerenol-m (a few thousandths of wt.%) has a very strong structuring effect on the sealing water and, as a consequence, on the resulting aerated concrete. [ABSTRACT FROM AUTHOR]

Aging of binders is a complex phenomenon which reduces the longevity of flexible pavements. Aging involves change in physical, chemical, and morphological properties of binder which makes the binder brittle and highly susceptible to fatigue and thermal cracking. Antiaging additives enhance the service life of flexible pavements by reducing the impact of aging on the performance of binders. An iterative approach is essential to identify the optimal dosage of antiaging additive necessary to counteract the aging effects on binder. The present study aims to evaluate the mixing conditions for uniform dispersion of carbon black and hydrated lime within the binder matrix and thereby evaluate the impact of incorporating these antiaging additives on the conventional properties of binder. For this purpose, varying proportions of carbon black and hydrated lime are added to VG 30 binder and is subjected to softening point, ductility, and penetration tests. The optimal dosage of carbon black and hydrated lime is found to be 6 and 12% respectively based on their significant effects on the conventional properties of the binder. An optimal mixing duration of 60 and 75 min ensures uniform dispersion of carbon black and hydrated lime within the binder matrix at a mixing temperature of 120 °C and a speed of 1000 rpm thereby producing a homogenous binder mastic. Incorporation of antiaging additives up to the optimal dosage enhances the softening point whereas decreases the penetration and ductility of binder. The increase in softening point of binder with incorporation of carbon black and hydrated lime signifies enhanced resistance to rutting and permanent deformation of binder, whereas the reduction in ductility and penetration of binder with incorporation of carbon black and hydrated lime signifies the reduced susceptibility of binder to environmental factors such as temperature fluctuations, UV radiation, and oxidation. The surface texture of the additive influences the ability of binder adsorption, which subsequently affects the rheological properties of binder mastics. Significant improvement in conventional properties of binder with incorporation of carbon black and hydrated lime paves a viable and cost-effective solution for engineering application as it has a subsequent effect on the rheological properties of binder. [ABSTRACT FROM AUTHOR]

Purpose: Bioceramic coatings have been shown to promote bone repair, which aids in the early integration of implants. This study aimed to evaluate the influence of air abrasion with a bioceramic abrasive on the surface characteristics of different implant materials and surfaces. The dissolution of the applied treatment from the surfaces over 3 weeks was also assessed. Materials and Methods: Discs of three alloys used for dental implants were studied and compared: two types of commercially pure titanium (CpTi)/ (CpTi SLActive) and titanium‐zirconia (TiZr). The tested surfaces were: CpTi control (CpC), sandblasted (SB), sandblasted and acid‐etched (SBE), and CpTi SLActive®, (TiZr) Roxolid®. Three discs from each group underwent air abrasion with apatite bioceramic powders, 95% hydroxyapatite (HA)/5% calcium oxide (CaO), and 90% hydroxyapatite (HA)/10% calcium oxide (CaO). The treated discs were surface characterized by optical profilometry to obtain surface roughness, scanning electron microscopy (SEM), and energy dispersive X‐ray spectroscopy (EDS) to compare element weight percentages of titanium, calcium, and phosphate. Dissolution was assessed using inductively coupled plasma optic emission spectrometry (ICP‐OES). Results: Bioceramic powders were deposited on all tested surfaces leading to changes in surface characteristics. The only statistically significant differences between the material groups for surface roughness were found with 95% HA/5% CaO powder in the Sp and Rp parameters (p = 0.03 and 0.04, respectively). There were no significant differences in the Ca and P wt% between all groups and powders 95% HA/5% CaO and 90% HA/10% CaO (p = 0.14, 0.18, and p = 0.15, 0.12, respectively). A non‐uniform dispersion of the treatment on the surface layer was visible on all treated surfaces. The bioceramic powder continued to dissolute from the tested surfaces for 3 weeks. Conclusion: Bioceramic abrasion modifies implant surface characteristics, although the change in surface characteristics resulting from such treatment was not influenced by the implant material or surface treatment. Air abrasion with hydroxyapatite and calcium oxide bioceramics leaves powder deposits on the treated implant surfaces that could potentially influence the healing of implants affected by peri‐implantitis. [ABSTRACT FROM AUTHOR]

Herein, for developing colored photocatalysts, calcium manganese oxide (Ca–Mn–O) film and powder samples are synthesized by a sol–gel method using acetylacetone (acac) or citric acid as a chelating agent, and their color and photocatalytic properties are evaluated. Thin‐film X‐ray diffraction experiments clarify the precipitation of Ca–Mn–O phases, such as Ca3Mn2O7 (Ca/Mn = 1.5) and Ca2MnO4 (Ca/Mn = 2), in the film samples with drop‐cast coating. These films strongly absorb all visible light due to the interband transition between O 2p and Mn 3d orbitals, resulting in dark gray coloration. By testing photocatalytic activities using methylene blue dyes, it is revealed that the film sample (acac, 4‐drops) exhibits photocatalytic activities, which makes Ca–Mn–O films dual functional with photocatalytic functions and coloration. [ABSTRACT FROM AUTHOR]

This paper proposes a mechanical dispersion method of hydrated lime in a vibrating activator equipped with special blades that operate in a resonant mode. It has been found that during the vibro-activation process, hydrated lime consistently passes through proportionately increasing stages of dynamic viscosity, slowing its growth and ceasing dispersion. A new vibration method for determining the viscosity of the hydrated lime-water system has been developed. The effect of vibration treatment on changes in the dispersion of calcium hydroxide was studied. It has been found that vibration-treated lime, compared to conventional hydrated lime, has new properties: the ability to form durable coatings due to accelerated carbonization. [ABSTRACT FROM AUTHOR]

This study aimed to compare calcium oxide (CaO) and calcium chloride (CaCl2) as calcium sources for coconut fatty acid distillate (CFAD) calcium soap (Ca-soap) production and to evaluate the supplementation ratios of unprotected and protected CFAD in dairy rations to optimize rumen function. This research included two steps: (1) assessing the protection strength of Ca-soap made with CaO and CaCl2 at mole ratios of Ca to CFAD of 1, 1.5, 2, and 2.5; (2) evaluating CFAD supplementation in an in vitro dairy ration study using a 5 × 4 randomized factorial block design. Factor A compared unprotected and protected CFAD ratios of A1 = 100:0, A2 = 75:25, A3 = 50:50, A4 = 25:75, and A5 = 0:100, and factor B compared supplementation levels of B1 = 0%, B2 = 1%, B3 = 2%, and B4 = 3%. CaCl2 at a 2.5-mole ratio to CFAD produced the lowest acid value and the carboxylic acid (C=O) chemical bond. Complete protection (0:100) exhibited the highest densities of Bacteroides and nutrient digestibility (p < 0.05) without significantly affecting rumen fermentability (p > 0.05). Higher CFAD levels significantly reduced methanogens and protozoa (p < 0.05) without significantly affecting estimated methane production. In conclusion, CaCl2 at a 2.5-mole ratio to CFAD provided the best protection, and its complete protection in CFAD supplementation optimized rumen function. [ABSTRACT FROM AUTHOR]

The construction sector is among the most polluting industries globally, accounting for approximately 37.5% of the European Union's total waste generation in 2020. Therefore, it is imperative to develop strategies to enhance the sustainability of this sector. This paper proposes a multiscale COMSOL Multiphysics numerical model for an ex situ mineral carbonation process of hydrated lime. The carbonation process is characterized at both the micro- and macroscale levels, encompassing interactions within and between the particles. This model incorporates both reaction and diffusion phenomena, considering the effects of porosity and liquid-water saturation parameters. Generally, liquid-water saturation enhances the reaction kinetics but not CO2 diffusion, while porosity improves CO2 diffusion throughout the granular bed. The model has been experimentally validated, showing promising results by accurately characterizing carbonation tendencies and the influence of the CO2 flow rate and the initial water-to-solid ratio on the carbonation process. The proposed mathematical model facilitates the study of various parameters, including particle radius, reactor geometry, and material porosity. This analysis is valuable for both current and future projects, as it aims to identify the most profitable configurations for the hydrated lime carbonation process. [ABSTRACT FROM AUTHOR]

A heterogeneous base catalyst transesterification process with a calcium oxide (CaO) catalyst was performed to produce high-purity methyl ester (ME) from pretreated sludge palm oil (PSPO) derived from sludge palm oil (SPO). Additionally, a comparative analysis was conducted with potassium hydroxide (KOH) as a homogeneous base catalyst to assess the distinctions between heterogeneous and homogeneous base catalysts. The response surface methodology (RSM) was utilized to determine the optimal and recommended conditions for both transesterification processes. For heterogeneous transesterification, a varying CaO catalyst loading (10–60 wt.%), methanol (25–65 wt.%), and reaction time (60–180 min) were essential parameters. Meanwhile, homogeneous transesterification involved investigating the KOH catalyst loading (1–3 wt.%), methanol (1.8–5.5 wt.%), and reaction time (20–60 min). For the heterogeneous-base-catalyzed reaction, the recommended conditions were as follows: a molar ratio of methanol to oil of 5.83:1 (41.61 wt.%), 31.3 wt.% CaO, and a reaction time of 119.0 min, which resulted in a ME purity of 96.51 wt.%. The optimal conditions for homogeneous transesterification were a molar ratio of methanol to oil of 0.49:1 (3.45 wt.%), a 40 min reaction time, and a 1.39 wt.% KOH concentration, which achieved 96.59 wt.% ME and met the standard. [ABSTRACT FROM AUTHOR]

Simple Summary: Fluctuations of physiological characteristics play an important role in a living organisms' normal existence and adaptation to environmental conditions. An important feature of oscillations in living systems is their ability to form (synchronization) or break links (desynchronization) with each other. For example, synchronization/desynchronization in the brain's electrical activity plays a role in memory and learning; synchronization changes cause epilepsy and other diseases. The task of quantifying the synchronization of signaling events in cells is currently unsolved. No universal, informative and accurate method has been found for assessing the synchronization of large cell groups. For the first time, we have tested the possibility of applying a mathematical method called bispectral analysis (applied earlier on the whole organism) to assess the coupling of signaling molecules and the level of fluctuations in cells. This method allows for a highly accurate estimation of the connection of oscillations between all pairs of cells in a studied population, the magnitude and frequency of these coupled oscillations, and which cells create and receive a "signal to form a connection of oscillations". We have shown that stress (overheating and excessive glucose concentration) changes the synchronization of oscillations of signaling molecules in cells. The obtained data can be applied in medicine and human economic activity. The oscillation synchronization analysis in biological systems will expand our knowledge about the response of living systems to changes in environmental conditions. This knowledge can be used in medicine (diagnosis, therapy, monitoring) and agriculture (increasing productivity, resistance to adverse effects). Currently, the search is underway for an informative, accurate and sensitive method for analyzing the synchronization of oscillatory processes in cell biology. It is especially pronounced in analyzing the concentration oscillations of intracellular signaling molecules in electrically nonexcitable cells. The bispectral analysis method could be applied to assess the characteristics of synchronized oscillations of intracellular mediators. We chose endothelial cells from mouse microvessels as model cells. Concentrations of well-studied calcium and nitric oxide (NO) were selected for study in control conditions and well-described stress: heating to 40 °C and hyperglycemia. The bispectral analysis allows us to accurately evaluate the proportion of synchronized cells, their synchronization degree, and the amplitude and frequency of synchronized calcium and NO oscillations. Heating to 40 °C increased cell synchronization for calcium but decreased for NO oscillations. Hyperglycemia abolished this effect. Heating to 40 °C changed the frequencies and increased the amplitudes of synchronized oscillations of calcium concentration and the NO synthesis rate. The first part of this paper describes the principles of the bispectral analysis method and equations and modifications of the method we propose. In the second part of this paper, specific examples of the application of bispectral analysis to assess the synchronization of living cells in vitro are presented. The discussion compares the capabilities of bispectral analysis with other analytical methods in this field. [ABSTRACT FROM AUTHOR]

Calcite is one of the significant components used in the wall tile application at a rate of 10–12% as its content contributes to the formation of pores. This study investigates the usability of snail shell waste with high calcium oxide content as an alternative to calcite raw material. Thus, depletion of calcite reserves will be prevented and value-added commercial products will be obtained by using waste. In addition, proper waste management will prevent environmental pollution and damage caused by waste accumulation. The chemical analysis of snail shell waste revealed a CaO content of 55%, while the CaO content in calcite was measured at 58%. Considering their similar chemical properties, different amounts of snail shell waste (%6, %9, %12) were added to the wall tile recipe instead of calcite. The addition of snail shell waste to the recipe resulted in an increase in sludge density and viscosity. Physical and mechanical tests were conducted on wall tiles made with the addition of snail shell waste and compared to standard wall tiles according to TSE EN ISO standards. When the waste material was used in a 50–50 ratio with calcite, the strength of the recipe was calculated to be 279.41 kg/cm2. Water absorption values were within standard limits and recorded at 15%. The phases that occur in the structure of wall tiles with the increase of waste addition were examined by X-ray Diffraction Analysis. The microstructures of the samples were compared with SEM–EDX analysis. Sustainable and low-cost wall tiles were obtained through the use of snail shell waste, with environmentally friendly solutions. [ABSTRACT FROM AUTHOR]

This feasibility study investigates the potential use of shrimp shell waste derived from peeled fresh and dried shrimp as a source of calcium (Ca) to produce value-added products (VAP). Thermal treatment of the samples was carried out by calcination at temperatures ranging from 200 to 1000 °C, and the resulting products were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analyses. The results show that the shrimp shell waste changes from black to white powder, with increasing temperature during the calcination of the carbon combustion, as proven in the thermogravimetric's (TGA) weight loss profile. The percent calcium recovery increased from 29.51 to 71.47%, and the optimum calcination temperature was reached at 1000 °C for both dried (DSS 1000) and fresh (FSS 1000) shrimp shell wastes. Spectral analysis showed that the hydroxyapatite (HAp) using calcium oxide (CaO) from FSS 1000 sample corresponded to the characteristic peaks of hydroxyapatite (JCPDS No. 9001233), while HAp produced from Ca DSS 1000 was identified as carbonate hydroxyapatite (JCPDS No. 9003552). The properties and quality of the calcium element varied according to the process used to produce shrimp shell waste. Therefore, the study suggests that shrimp shell waste could be a valuable resource for calcium recovery while mitigating the negative impacts of waste disposal on the ecosystem. [ABSTRACT FROM AUTHOR]

To improve the resource utilization of dredged silt and industrial waste, this study explores the efficacy of using ground granulated blast furnace slag (GGBS), active calcium oxide (CaO), and sodium silicate (Na2O·nSiO2) as alkali activators for silt stabilization. Through a combination of addition tests, response surface method experiments, and microscopic analyses, we identified key factors influencing the unconfined compressive strength (UCS) of stabilized silt, optimized material ratios, and elucidated stabilization mechanisms. The results revealed the following: (1) CaO exhibited the most pronounced stabilization effect, succeeded by Na2O·nSiO2, whereas GGBS alone displayed marginal efficacy. CaO-stabilized silt demonstrated rapid strength augmentation within the initial 7 d, while Na2O·nSiO2-stabilized silt demonstrated a more gradual strength enhancement over time, attributable to the delayed hydration of GGBS in non-alkaline conditions, with strength increments noticeably during later curing phases. (2) Response surface analysis demonstrated substantial interactions among GGBS-CaO and GGBS-Na2O·nSiO2, with the optimal dosages identified as 11.5% for GGBS, 4.1% for CaO, and 5.9% for Na2O·nSiO2. (3) X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses clarified that the hydration reactions within the GGBS-Na2O·nSiO2 composite cementitious system synergistically enhanced one another, with hydration products wrapping, filling, and binding the silt particles, thereby rendering the microstructure denser and more stable. Based on these experimental outcomes, we propose a microstructural mechanism model for the stabilization of dredged silt employing GGBS-CaO-Na2O·nSiO2. [ABSTRACT FROM AUTHOR]

This study aims to compare the effects of three calcium compounds on the workability, setting time and mechanical properties of red mud (RM)–blast furnace slag (BFS)-based geopolymers. The crystalline phase, hydration process and microstructure of RM-BFS-based geopolymers were characterized by X-ray diffraction (XRD), heat evolution, X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) tests. The results showed that an appropriate amount of calcium compounds can improve the flowability and compressive strength of the geopolymers, but the excessiveness causes a decrease in strength due to rapid hardening. Other than calcium carbonate, both calcium oxide and calcium chloride played important roles in accelerating the setting times of RM-BFS-based geopolymers. The acceleration in the setting times of geopolymers could be attributed to the calcium hydroxide produced by the dissolution of the calcium compounds, which also provides nucleation sites for the geopolymerization reaction. This study gives new insights into the effect of calcium on the setting times and mechanical properties of geopolymers in the geopolymerization process. [ABSTRACT FROM AUTHOR]

The utilization of biopolymers incorporated with antimicrobial agents is extremely interesting in the development of environmentally friendly functional materials for food packaging and other applications. In this study, the effect of calcium oxide (CaO) on the morphological, mechanical, thermal, and hydrophilic properties as well as the antimicrobial activity of carboxymethyl chitosan (CMCH) bio-composite films was investigated. The CMCH was synthesized from shrimp chitosan through carboxymethylation, whereas the CaO was synthesized via a co-precipitation method with polyethylene glycol as a stabilizer. The CMCH-CaO bio-composite films were prepared by the addition of synthesized CaO into the synthesized CMCH using a facile solution casting method. As confirmed by XRD and SEM, the synthesized CaO has a cubic shape, with an average crystalline size of 25.84 nm. The synthesized CaO exhibited excellent antimicrobial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) (>99.9% R). The addition of CaO into CMCH improved the mechanical and hydrophobic properties of the CMCH-CaO films. However, it resulted in a slight decrease in thermal stability. Notably, the CMCH-CaO10% films exhibited exceptional antimicrobial activity against E. coli (98.8% R) and S. aureus (91.8% R). As a result, such bio-composite films can be applied as an active packaging material for fruit, vegetable, or meat products. [ABSTRACT FROM AUTHOR]

An approach for the efficient re-utilisation of waste cement paste powders is proposed, wherein the powders are heated to a certain temperature to prepare regenerated binding materials (RBMs), and then rapidly carbonated by high-concentration carbon dioxide to prepare high-strength products. The structural evolution during the heating process of waste cement paste powder and the carbonation process of RBMs were investigated by X-ray diffraction analysis, scanning electron microscopy and 29Si nuclear magnetic resonance spectrum, and the compressive strength of the carbonated RBM samples was measured. The results show that the differences in carbonation reactivity, carbonation products of the RBMs and properties of carbonated RBMs can mainly be attributed to the differences in the degree of structural order of newly formed β-dicalcium silicate (C2S), the content of β-C2S, free calcium oxide (f-CaO) and incompletely decomposed calcium silicate hydrate (C–S–H) in RBMs. The strength of the carbonated sample of RBM prepared at 1050°C was the highest, followed by that prepared at 950°C, which was significantly higher than those prepared at 650, 750 and 850°C. The content of highly ordered β-C2S in RBMs with high carbonation reactivity and the dense stacking of the carbonation products are beneficial for the mechanical properties. [ABSTRACT FROM AUTHOR]

The effect of calcium addition on inclusions (oxides and sulfides) in heavy steel ingot is investigated via lab experiments and thermodynamic calculation. The characteristics (chemistry, size, morphology, and number) of inclusions in the steel samples are investigated by scanning electron microscope with an energy‐dispersive spectrometer. The three‐dimensional morphology of inclusions is investigated by the nonaqueous solution electrolysis method. Inclusions in the fast‐quenched steel are changed from Al2O3 to Al2O3–CaO, Al2O3–CaO–CaS, and CaS after Ca addition. After slow cooling, inclusions in the solid steels are changed from Al2O3, single MnS, and Al2O3–MnS complex inclusions to Al2O3–CaO–CaS–MnS and CaS–MnS. The evolution trajectory of inclusions is Al2O3→Al2O3–CaO→Al2O3–CaO–CaS→Al2O3–CaO–CaS–MnS. With increasing Ca content in the steel, the number density and proportion of single MnS inclusions decrease. The formation mechanism of inclusions after Ca addition is explained by thermodynamic calculation. [ABSTRACT FROM AUTHOR]

This study shows how the presence of metal-impregnated biochar influences the kinetics of the catalytic conversion of waste motor oil (WMO) into a diesel-like fuel (DLF). First, the initial metal concentration in the wet impregnation process was optimized, showing that high metal concentrations tend to clog the biochar pores, reducing the reaction's conversion and speed. Zinc and calcium showed higher kinetic constants at the optimized conditions than nickel, while the yield- and selectivity-to-liquid products were unaffected. Then, a reduction method was developed for impregnating metal particles of calcium oxide to enhance the metal dispersion at the biochar surface. This material showed the best performance in the reaction due to the presence of small particles instead of metal agglomerates. An increase of about 280% in the kinetic constant at 420 °C and a much lower activation energy (246 kJ mol−1) compared to the thermal cracking (308 kJ mol−1) was obtained. Finally, the DLF from the best catalytic system was analyzed. Interestingly, the fuel showed similar rheological properties to commercial diesel with a similar hydrocarbon distribution but with the presence of smaller hydrocarbon chains. [ABSTRACT FROM AUTHOR]

In this research, the production and wear behavior of CaO and MgO doped stabilized zirconia ceramics prepared by powder metallurgy method were investigated and artificial neural network (ANN) models were established and predicted with the data produced as a result of real experiments. CaO/MgO doped stabilized zirconia ceramics were produced using a combination of ball milling, cold pressing - cold isostatic pressing and sintering methods. CaO and MgO were mixed with zirconia in different amounts (0-8 mol%). These mixtures were prepared by mechanical alloying. Green compacts were sintered at 1600°C. The wear experimental results produced from the trials were converted into data suitable for modelling with ANN. Wear load, wear time of the load, MgO and CaO were given as input to the ANN model. The amount of wear according to the pressing method was set as the output variable value of the ANN. An ANN approach model was established to predict the wear behavior characteristics of zirconia ceramic composites. In order to emphasize the success of the model, the test data set was presented to the ANN model and the results produced were compared with the results produced experimentally, and as a result of these tests, high R2 values of 0.99409 for 65N and 0.97512 for 80N were produced. [ABSTRACT FROM AUTHOR]

For thousands of years, mortar-based materials — including bedding mortars, plaster floors, internal wall plasters, external wall renders and stuccos, and concrete — have been key construction materials in many cultures throughout the world. This paper gives an overview and examples of the use and development of mortar-based materials in cultures across the Middle East, Europe, Asia, and Mesoamerica, prior to the development of hydraulic cements in the late 18th and early 19th centuries. [ABSTRACT FROM AUTHOR]