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Synthesis and characterization of a Dy3+-activated calcium yttrium oxide (CaY2O4) phosphor are reported. The CaY2O4:Dy3+ (1.5 mol%) phosphor is synthesized using a modified solid-state reaction technique for calcination and sintering. The cubic structure is revealed by the X-ray diffraction technique. The morphology and particle size distribution of the prepared phosphor are investigated by the FEGSEM technique. The chemical bonds and functional group analysis are confirmed by the FTIR. A photoluminescence analysis of the CaY2O4:Dy3+ phosphor shows dual excitation wavelengths at 285 and 348 nm, especially in the ultraviolet region. At 383 nm, three distinct emission peaks are found at the wavelengths 238, 485, and 571 nm. The spectroscopic parameters are calculated using the CIE chromaticity coordinates. The CIE coordinates of the Dysprosium ion-activated CaY2O4 phosphor (1.5 mol%) show an emission near the white light region of the chromaticity diagram, suggesting that it is suitable for W-LED applications. [ABSTRACT FROM AUTHOR]

The Size-Strain Plot (SSP) method has been modified and optimized for improved X-ray diffraction (XRD) analysis, particularly focusing on its application in probing the structural properties of pure and Ca-doped zinc oxide nanoparticles (Zn1 − xCaxO, x = 0.0: ZnO, x = 0.01: ZCa1, x = 0.03: ZCa3, x = 0.05: ZCa5). Zn1 − xCaxO nanoparticles were synthesized by a gelatin-based sol-gel method. Through rigorous experimentation and analysis, the optimized SSP method demonstrates enhanced accuracy and reliability in determining crystallite size and lattice strain. The structural properties of Zn1 − xCaxO, including crystallite size distribution and lattice strain effects, are thoroughly investigated, shedding light on the underlying mechanisms influencing ZnO's structural behavior. This refined SSP method offers valuable insights into the nanostructural characteristics of Zn1 − xCaxO, contributing to advancements in material science and nanotechnology. Also, the optical properties of the prepared samples were investigated in the UV-vis range. The results showed that adding calcium to zinc oxide with the mentioned amounts does not cause significant changes in its structure and optical properties. [ABSTRACT FROM AUTHOR]

The increased prominence in the use of nanoparticles has made it important to employ synergy between nanoparticles while harnessing individual metallic and biological properties to improve and modify the surface, the versatility, and efficiency of nanoparticle hybrid. This study aims to conduct a bio-assessment assay of nanoparticle hybrid systems within an in-vitro set-up and improve the surface modifications of these systems. The hybrid surfaces are characterized using a scanning electron microscope, dynamic light scattering (DLS), X-ray diffraction analysis (XRD), and Fourier-transform infrared spectroscopy (FTIR). FTIR reveals the presence of functional groups like phenols, carboxylic acids, and esters. The XRD confirms the hexagonal crystalline phase of Fe-NZnO, the cubic lattice of Fe-NCaO, and the rutile phase of TiO2. The hydrodynamic diameter of Fe-NZnO-NCaO, Fe-NTiO2-NCaO, and Fe-NTiO2-NZnO are shown to be 163.2, 164.6, and 219.4 nm, respectively, using DLS analysis. Turbidity analysis indicates that Fe-NZnO-NCaO is the least aggregated particle following a 14-day observation period, meaning that it is the most stable over that period. Anti-hemolytic erythrocyte assay demonstrates the relative biocompatibility and ability of the hybrids to enhance cell protein protection. Fe-NZnO-NCaO and Fe-NTiO2-NCaO exhibit higher post-treatment cytotoxicity across the concentrations than Fe-NTiO2-NZnO. [ABSTRACT FROM AUTHOR]

This study involved fortifying pumpkin slices with calcium and vitamin D3 using vacuum impregnation (VI) pre‐treatment and assessing the quality characteristics of the resulting desserts/jams. Slices were subjected to immersion or VI pre‐treatments for 30, 60, and 90 min in a solution containing calcium oxide and vitamin D3. Calcium ions contributed to the hardness of desserts, with VI reducing processing time. The highest impregnated calcium (58.17 mg/100 g fw) and vitamin D3 contents (6.02 mg/100 g dm) were determined in slices pre‐treated by VI for 90 min. VI was more effective than immersion in terms of calcium and vitamin D3 transition into pumpkin tissues. Scanning electron microscope (SEM) images indicated that calcium oxide particles were noticeable in slices pre‐treated by VI. Immersing fruit slices for 90 min produced desserts with a textural hardness of 11.04 N, while VI pre‐treatment for the same duration increased their hardness value to 18.92 N. Desserts produced with VI‐pre‐treated slices exhibited superior texture and sensory attributes, with no adverse taste resulting from calcium oxide. In conclusion, VI pre‐treatment shows significant potential for the industrial production of desserts/jams with enhanced structural integrity for fruits. [ABSTRACT FROM AUTHOR]

The article provides information on an experiment conducted at farmers' field in potato during the year 2022-2023 by application of lime to ameliorate the soil acidity for better production of potato in three villages of Lakhimpur District of Assam, India. Topics include initial soil status of the experimental sites, effect of lime application on yield and plant height of potato, and correlation relationship between yield and soil parameters as affected by lime.

The high‐value utilization of blast furnace slag (BFS) and steel slag (SS) as a valuable resource in the field of carbon reduction represents a green revolution, and also is an indispensable path toward breaking through resource and environmental constraints and achieving high‐quality, sustainable development through solid waste utilization in the steel industry. Achieving resource recycling while harnessing the untapped latent energy of resources and exploring their carbon sequestration capabilities has become a crucial avenue for further valorization through waste utilization. BFS and SS discharged from iron‐making or steel‐making furnaces carry a significant amount of latent heat, especially the calcium oxide component in SS, which gives it a unique advantage in the field of comprehensive BFS and SS utilization and carbonation‐based SS utilization. This article discusses the current research status of low‐carbon‐waste‐heat utilization in the production of microcrystalline glass, cementitious materials, functional adsorbents, and other products through front‐end modification of molten BFS and SS. This report also provides an overview of carbon capture by utilizing BFS and SS, offering insights into the research directions for subsequent heat recovery, online quality adjustment, high‐value utilization, and carbon sequestration using BFS and SS in the steel industry. [ABSTRACT FROM AUTHOR]

A technology for the hydrochemical processing of the kaolinite fraction of bauxite has been developed, and it involves preliminary chemical activation in a sodium bicarbonate solution and alkaline leaching in a recycled high-modulus solution with the addition of an active form of calcium oxide. Chemical activation allows for the transformation of the difficult-to-explore kaolinite phase to form easily soluble phases of dawsonite, sodium hydroaluminosilicate and bemite. An active, finely dispersed form of calcium oxide was obtained as a result of CaO quenching in Na2SO4 solution at elevated temperature and pressure. Using a central composite design (CCD) via response surface methodology (RSM), the technological leaching mode was achieved. The influence on the leaching process was studied by adjusting the CaO/SiO2 ratio, temperature, alkaline solution concentration and duration. It was found that the determining factors are the concentration of the leaching solution and the temperature. At a stable CaO/SiO2 ratio, a combination of these two factors determines the duration of the process to achieve the predicted degree of recovery. The results of experiments carried out using the developed model of the leaching process confirmed the validity of the calculated indicators, with an error of 2.01%. In an optimal technological mode at a Na2O leaching solution concentration of 260 g/L, a temperature of 260 °C, a CaO/SiO2 ratio of 1.5 and a leaching time of 5 h, the extraction of Al2O3 into the solution was 89.7%, which is close to the value of 87.9% predicted by the model. [ABSTRACT FROM AUTHOR]

The use of alumina-containing nepheline raw materials as an alternative source of alumina is relevant in the context of the limited bauxite reserves in Kazakhstan. Nepheline processing can result in products such as alumina, sodium and potassium salts, silicate products and rare metals. In terms of economic value, alumina is the most important. This article considers an advanced technology for nepheline processing for the extraction of alumina that is first purified from potassium. The application of calcium sulphate and calcium oxide as additives to the nepheline raw materials is studied. The optimal conditions for two-stage leaching with calcium additives in the form of calcium sulphate and calcium hydroxide are determined. [ABSTRACT FROM AUTHOR]

Metro transit construction has begun to develop rapidly in northwest China because of the acceleration of urbanization. Accordingly, metro depots are also regarded as an essential auxiliary facility for stopping, operation, and maintenance of trains. Meanwhile, many commercial buildings are constructed over metro depots to improve the utilization rate of land due to the increasingly scarce urban land resources, known as transit-oriented development (TOD). These buildings have a large covered area and transfer concentrated loads to the bases. Therefore, pile bases under metro depots have the bearing characteristics of undertaking large concentrated loads, while lesser loads are placed on the soil between the adjacent pile bases. Additionally, the main ground in northwest China is collapsible loess, so the collapsibility should also be considered. Based on the above background, this research performed static loading tests with and without immersion in a reduced scale of adjacent pile bases under a metro depot in Xi'an. The remolding process of natural loess could destroy its structure and the anisotropy of natural loess could also affect the test results. Therefore, four kinds of artificial collapsible loess with different mass ratios of barite powder, kaolin, river sand, cement, industrial salt, and calcium oxide were made by the free-drop method. This method could make the artificial loess simulate the structure of natural loess reasonably. Then, the artificial loess with the most similar properties to intact loess was selected by comparison. Finally, static loading tests with this artificial loess were implemented. The results showed that the ultimate bearing capacity was 4.5 kN. At the same time, the axial force decreased along depth, since the pile shaft friction was positive, and the load sharing ratio of pile tip force increased to 0.58 when the load exceeded 4.5 kN in the situation without immersion; the settlement of pile bases increased significantly after immersion, while the negative shaft friction occurred at the depth of −8 cm~−35 cm, and the load sharing ratio of pile tip force reached 0.92. [ABSTRACT FROM AUTHOR]

Gypsum products (calcium sulfate dihydrate, CaSO4·2H2O) were synthesized through an eco-friendly and low-cost process by two different renewable calcium carbonate sources (CaCO3), hen and duck eggshell wastes, with product yields obtained of 84.73 and 87.74%, respectively. The X-ray fluorescence results indicated that calcium oxide (CaO) and sulfur trioxide (SO3) are the major elemental components of CaSO4·2H2O prepared from both calcium sources. The Fourier transform infrared results confirmed the vibrational characteristics of SO42− and H2O functional groups in the chemical structure of the prepared samples. The X-ray diffraction patterns of CaSO4·2H2O prepared from both calcium sources confirmed the sample's crystal structure as well as the chemical formula, after comparing them to the standard powder diffraction file. The crystallite sizes of CaSO4·2H2O products were calculated from the experimental diffraction peak through the Scherrer equation and found to be 19–20 nm. The positive preferential growth (Pg) value highlighted the excellent stability of the synthesized CaSO4·2H2O. The scanning electron microscopic results showed the agglomeration particles of hen- and duck-CaCO3 raw agents, whereas plate-like particles were observed for hen- and duck-CaSO4·2H2O products but the particle sizes were different. [ABSTRACT FROM AUTHOR]

Mortar that is typically employed for interior or exterior coatings can be characterised using laboratory-prepared specimens according to specific test standards; however, its performance undergoes changes following application on substrates. When selecting mortar, it is vital to anticipate its in-service behaviour after its application on substrates to make the most informed choice. Most of the research work carried out to date analyses the characteristics of mortar in laboratory specimens. Some studies analyse these characteristics after its application to support, but very few exist that compare both behaviours. With this objective in mind, this research determined the properties of mortar when cured within laboratory moulds and assessed the behaviour of the same mortar after application on diverse substrate types. This study specifically evaluated the behaviour of a pre-dosed hydraulic lime mortar when applied on concrete blocks, lightweight concrete blocks, concrete slabs, hollow ceramic bricks, and solid ceramic bricks. Later, this behaviour was compared to the same type of mortar hardened in laboratory moulds and the same type of mortar applied on substrates and subjected to accelerated ageing. Moreover, data from previous experimental work were used to compare the behaviour of the pre-dosed hydraulic lime mortar with that of pre-dosed cement mortar when applied on similar substrates. The research drew upon a comprehensive characterisation of the physical and mechanical parameters of mortar, revealing that the performance of these types of mortar undergoes significant changes after application on substrates under in-service conditions, mainly when applied on more porous substrates. It was concluded that the application of mortar to substrates increased bulk density, decreased open porosity, enhanced compressive strength, and resulted in faster capillary absorption. For mortars subjected to accelerated ageing, a notable reduction in water vapour permeability was observed, which was attributed to changes in the pore profile. [ABSTRACT FROM AUTHOR]

Energy conservation and sustainability to reduce the dependence on conventional sources have resulted in modified or advanced process practices. One such is the use of nanofluids for enhanced energy efficiency. However, such practices must not be at the cost of environmental hazards. The current study emphasizes bio‐based nanofluids formulated at five different volumetric concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) using Flamboyant (Royal Poinciana) tree bark nanoparticles with ethylene glycol as base fluid. The nanoparticles synthesized by cost‐effective extensive ball milling technique were spherical in shape. Analyzing the nanofluid with TEM confirms the particles as evenly distributed with an average diameter of 26 nm. Elemental analysis shows that the bio powder contains oxides of Calcium and Silicon. The pH, electrical conductivity, and viscosity of the prepared flamboyant tree bark‐ethylene glycol (FTB‐EG) nanofluid were quantified between 20 and 70°C. Although the properties enhanced with increase in concentration, the viscosity and pH decreased with temperature rise, while the electrical conductivity behaved contradictory. The maximum and minimum values of the properties were attributed to 1.0% and 0.2% concentrations, respectively. The correlations were proposed and the deviation between the measured and correlation data was less than 10%. [ABSTRACT FROM AUTHOR]

Granulated truck waste tire was first pyrolyzed in a fixed‐bed reactor under an inert atmosphere and at certain conditions. The highest oil yield of which was 47.0 wt %, was attained at 550 and 20°C/min. The oil was separated into a fraction of 150–300°C boiling points, so‐called diesel‐like fuel (DBY), with a calcium oxide (CaO) catalyst at an optimal ratio of 2 wt %. The fraction was subjected to desulfurization, bleaching, and deodorization, respectively, at specific conditions, and this process resulted in a decrease of 75.8 wt % compared to its initial sulfur content of 5000 ppm. The upgraded diesel‐like oil (DAF) fraction contained chemical compounds with carbon numbers C6–C26. In addition, its physicochemical characteristics showed a kinematic viscosity of 3.13 cSt (40°C), a density of 832 g/L (15°C), a lower heating value of 42.32 MJ/kg, and an H/C molar ratio of 1.73. Lastly, the DAF was tested with commercial diesel fuel for its motor and emission performance via a single‐cylinder diesel engine. All in all, it can be said that the DAF may be harnessed as a substitute for diesel fuels after its further upgrading via catalytic hydrodesulfurization etc. [ABSTRACT FROM AUTHOR]

Smouldering has recently been developed as a cost effective and energy efficient technology for challenging wastes. These systems are often used to eliminate environmental liabilities, and only minimal work has explored their use for generating useful by-products. This study addressed this research gap and demonstrated that applied smouldering systems can be tuned to favour hydrogen production. Calcium oxide and steam were added to the smouldering system, which completely treated woody biomass and coal tar, while producing hydrogen. The maximum hydrogen concentration achieved in the smouldering system was 33.7%, resulting in a net energy positive syngas. Results suggest that both heterogenous gasification and the water gas shift were key mechanisms behind hydrogen formation. These results indicate that smouldering systems can be used as a new method to sustainably produce hydrogen-rich syngas from challenging wastes. [Display omitted] • Experimental study produced up to 34% H 2 from smouldering combustion. • Experiments used different fuels, porous media, steam, and CaO amendments. • New methodology to drive net-energy-positive H 2 -rich syngas from smouldering. • Optimum steam/carbon ratio was found to be between 2 and 3 to maximize H 2 yield. • Heterogenous gasification and the water gas shift were key H 2 production mechanisms. [ABSTRACT FROM AUTHOR]

Lime (which exists as calcium oxide and calcium hydroxide) is typically obtained by calcinating limestone, which consists of calcium carbonate. The process releases large amounts of carbon dioxide (CO2) into the atmosphere. Calcium hydroxide (Ca(OH)2) may also be obtained by treating calcium carbonate or calcium sulphate with an alkaline aqueous solution. These processes generate Ca(OH)2 without calcinating limestone, thereby avoiding the emission of CO2. However, the use of alkaline chemicals may still be accompanied by a carbon footprint associated with the manufacturing process (for example, using electricity generated through the combustion of fossil fuels). In this study, we produced Ca(OH)2 using gypsum (calcium sulphate dihydrate) powder and wastewater containing a small amount of sodium hydroxide (NaOH). Our method constitutes an environmentally responsible process for producing lime, using resources harvested from demolishing buildings and returnable bottle-washing processes. Our results demonstrate that a small amount of NaOH in an aqueous solution can effectively transform gypsum into Ca(OH)2 and that the composition of Ca(OH)2 and gypsum can affect the NaOH content and reaction time. We establish a process for transforming wastewater treatment into resource recovery, producing lime in an environmentally responsible manner and augmenting the construction of a carbon-neutral society. [ABSTRACT FROM AUTHOR]

Alkali-activated slag (AAS) materials are one of the most promising sustainable construction composites. These novel materials are highly characterized by their improved mechanical and durability properties. Nevertheless, the high shrinkage rate hinders their full-scale applications. The low Ca/Si ratio, complex hydration process, and fine pore microstructure are the main causes of the reported shrinkage behavior. This study introduces Bacillus subtilis culture for healing the cracking behavior. The enzymatic action leads to precipitating calcium carbonate crystals that fill AAS cracks and pores. Incorporating calcium oxide has been recommended in multiple studies. The main purpose of adding calcium oxide is to enhance the engineering properties of AAS and provide more calcium ions for the biochemical reactions induced by the added bacteria. However, inconsistent findings about the influence of calcium oxide have been reported. This research provides further insights into the effect of calcium oxide (CaO) on the performance of microbial self-healing efficiency in AAS composite. The results highlight that incorporating calcium oxide as 7% of the binder partial replacement has an impact on the engineering properties of bio-AAS materials. The study recommends correlating the percentage of free calcium ions within the AAS mixture with the microbial activity. [ABSTRACT FROM AUTHOR]

In order to improve CeO 2 ultraviolet absorption performance and transparency, this paper puts forward that different proportions of calcium oxide are doped during the formation of CeO 2. Doping calcium ions with larger ion size and lower valence leads to the formation of oxygen defects by inhibiting the precipitation of oxygen from cerium oxide and keeps the fluorite structure of cerium oxide stable. The effects of CaO doping on the crystal structure, morphology, and optical characteristics of CeO 2 were analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis spectrophotometry. The pH of sunscreen, spread ability and some physical as well as chemical evaluations were carried out, while to study its UV protection performance the sunscreen SPF test was performed. The UV–vis results revealed that CeO 2 /20%CaO showed highly efficient UV absorption capacity. After adding calcium oxide, the catalytic activity of the material is reduced, due to which the generation of free radicals is demoted, and the harm to human body is decreased. After the addition of 3 wt% nanomaterials into sunscreen, the sun protection factor（SPF ）values of pure cerium oxide and CeO 2 /20%CaO are 1.95 and 2.81, and their sun protection coefficient is increased by 69.39%. Therefore, it is an ideal candidate as a component of ultraviolet screening agent in sunscreens and provides a new idea for the research direction of cerium oxide in anti-ultraviolet applications. [ABSTRACT FROM AUTHOR]

Immensely thermally stable and perfectly dense ceramics of highly pure calcium manganese oxide (CaMnO 3) powders is realized at optimized minimal processing temperature and time using cost-effective ball-milling and hot-press techniques. The effect of ball milling time on the calcination time to prepare highly pure CaMnO 3 powder and sintering time on the temperature adequate enough to achieve perfectly dense CaMnO 3 ceramics is studied thoroughly and systematically. The as-synthesized single phase CaMnO 3 is attained by mixing precursors of calcium carbonate and manganese oxide, using high energy ball milling for longer time followed by calcination for shorter time duration and vice-versa. A decrease in particle size in as-synthesized CaMnO 3 is noticed for powders prepared with longer ball milling and shorter calcination times. The minimal time required for achieving highly pure and fine-grained powders containing sub-micrometer particles of CaMnO 3 is accomplished by ball milling the precursor mixture for 12 h and calcining at 1273 K for 2 h. Relative density of 99.03% is achieved for the as-synthesized CaMnO 3 powders hot pressed at 1073 K for 30 min. [ABSTRACT FROM AUTHOR]

Virtually noiseless due to the scarcity of spinful nuclei in the lattice, simple oxides hold promise as hosts of solid-state spin qubits. However, no suitable spin defect has yet been found in these systems. Using high-throughput first-principles calculations, we predict spin defects in calcium oxide with electronic properties remarkably similar to those of the NV center in diamond. These defects are charged complexes where a dopant atom — Sb, Bi, or I — occupies the volume vacated by adjacent cation and anion vacancies. The predicted zero phonon line shows that the Bi complex emits in the telecommunication range, and the computed many-body energy levels suggest a viable optical cycle required for qubit initialization. Notably, the high-spin nucleus of each dopant strongly couples to the electron spin, leading to many controllable quantum levels and the emergence of atomic clock-like transitions that are well protected from environmental noise. Specifically, the Hanh-echo coherence time increases beyond seconds at the clock-like transition in the defect with 209Bi. Our results pave the way to designing quantum states with long coherence times in simple oxides, making them attractive platforms for quantum technologies. Recently, long spin coherence times have been predicted for spin defects in simple oxides. Here, by using high-throughput first-principles calculations, the authors identify promising spin defects in CaO, with electronic properties similar to those of NV centers but with longer coherence times. [ABSTRACT FROM AUTHOR]

Calcium oxide (CaO) is a promising host for quantum defects because of its ultrawide bandgap and potential for long spin coherence times. Using hybrid functional calculations, we investigate the intrinsic point defects and how they limit Fermi-level positions and doping in CaO. We find calcium and oxygen vacancies to be the most common intrinsic defects, acting as compensating acceptors and donors, respectively. Oxygen interstitials are also prevailing under O-rich conditions and act as compensating donors. Due to compensation by these defects, O-poor conditions are required to dope CaO n-type, while O-rich conditions are required for p-type doping. We find that, at room temperature, intrinsic CaO can only achieve Fermi-level positions between 1.76 eV above the valence-band maximum (VBM) and 1.73 eV below the conduction-band minimum (CBM). If suitable shallow dopants are found, the allowed range of Fermi levels would increase to between VBM + 0.53 eV and CBM − 0.27 eV and is set by the compensating intrinsic defects. Additionally, we study hydrogen impurities, and show that hydrogen will not only limit p-type doping but can also act as shallow donor when substituting oxygen ( H O defects). [ABSTRACT FROM AUTHOR]

The strength and durability properties of the recycled aggregate concrete (RAC) have been affected by the cracks and the weak interfacial transition zone (ITZ) of the recycled coarse aggregates (RCA). However, the mechanical and physical features of RCA can be improved by microbially induced calcite precipitation (MICP). Therefore, immobilization techniques were used to protect and maintain the high efficiency of Bacillus bacteria for the formation and precipitation of calcium carbonates in self‐healing concrete over a period of time. The objective of the present study was to show the viability of the immobilized bacterial consortium‐enhanced RCA to form self‐healing cracks. Further, the self‐healing capability of enhanced RCA was investigated along with two other immobilization methods, that is, RCA and hydrated lime and brick powder (HBr)‐immobilized bacteria. The experimental results show that the increase in the bio‐deposition time improved the physical and mechanical properties of the RCA. Further, subsequently 56 days of the healing incubation period, the immobilized consortium‐enhanced RCA concrete specimens completely healed the cracks of width 0.58 mm. However, the equivalent cracks of width 0.56 mm were also recovered by the HBr immobilized bacterial cultures. Furthermore, the field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS) and X‐ray diffraction (XRD) analysis revealed that the existence of precipitation at the crack surface was calcium carbonate with a regular cubic‐shaped and lamellar layer morphology. The outcomes of the current study show that consortium‐enhanced RCA has promising potential to develop self‐healing concrete with self‐repaired and improved durability properties in the concrete construction field. [ABSTRACT FROM AUTHOR]

Calcium‐ion batteries (CIBs) are considered as potential next‐generation energy storage systems due to their abundant reserves and relatively low cost. However, irreversible structural changes and weak conductivity still hinder in current CIBs cathode materials. Herein, an organic molecular intercalation strategy is proposed, in which V2O5 regulated with quinoline, pyridine, and water molecules are studied as cathode material to provide fast ion diffusion channels, large storage host, and high conductivity for Ca ions. Among them, V2O5‐quinoline (QVO) owns the largest interplanar spacing of 1.25 nm and the V‐O chains are connected with organic molecular by hydrogen bond, which stabilizes the crystal structure. As a result, QVO exhibits a specific capacity of 168 mAh g−1 at 1 A g−1 and capacity retention of 80% after 500 cycles at 5 A g−1 than the other materials. Furthermore, X‐Ray diffraction and X‐ray absorption spectroscopy results reveal a reversible order‐disorder transformation mechanism of Ca2+ for QVO, which can make full use of the abundant active sites for high capacity and simultaneously achieve fast reaction kinetics for excellent rate performance. These results demonstrate that QVO is a promising cathode material for CIBs, providing more choices for the development of high‐performance CIBs. [ABSTRACT FROM AUTHOR]

Fragility is commonly quantified as the magnitude of change in viscosity at a temperature close to the glass transition temperature (Tg). It is a critical characteristic of melts used in scientific and industrial applications. The fragility of silicate melts generally increases with the depolymerization of silicate anions upon the addition of alkali or alkaline earth oxides. However, the effects of oxide additives on the fragility of aluminosilicate melts remain unclear. In this study, the effect of CaO or K2O addition on the viscosity of the 36CaO–51SiO2–13Al2O3 (mol.%) melt for the wide viscosity range of 10−1–1012 Pa s was studied. The relationship between the logarithmic viscosity and Tg‐scaled temperature indicated that the melt fragility increased with the addition of CaO, whereas the addition of K2O reduced the fragility when the additive content of CaO or K2O was less than 10.8 mol.%. The effect of the addition of K2O on fragility cannot be explained by the depolymerization of silicate anions alone. Raman and 27Al nuclear magnetic resonance spectroscopies of the glasses indicated that a decrease in the level of distortion of the AlO4 tetrahedra decreased the fragility of the aluminosilicate melt. [ABSTRACT FROM AUTHOR]

Quicklime, rich in CaO(s), is generated by calcining limestone at high temperatures. Parallel-flow regenerative lime kilns are the most energy-effective industrial method available today. To prevent major disruptions in such kilns, a high raw material quality is necessary. Under some conditions, impurity-enriched material may adhere to limestone pebbles and enter the kiln. In this study, limestone and corresponding quicklime were analyzed to evaluate the extent and composition of surface impurities and assess the effect on quicklime product quality, here defined as free CaO. This was performed by sampling and analyzing limestone, quarry clay, laboratory-produced quicklime, and industrially produced quicklime with XRF, SEM/EDX, and XRD; interpretations were supported by thermodynamic equilibrium calculations. In the laboratory-produced quicklime, the surface impurities reacted with calcium forming Larnite, Gehlenite, Åkermanite and Merwinite, reducing the quicklime quality. The results showed that the limestone surface layer comprised 1.2 wt.-% of the total mass but possessed 4 wt.-% of the total impurities. The effect on industrially produced quicklime quality was lower; this indicated that the limestone surface impurities were removed while the material moved through the kiln. Multicomponent chemical equilibrium calculations showed that the quarry clay was expected to be fully melted at 1170 °C, possibly leading to operational problems. [ABSTRACT FROM AUTHOR]

Facade-rendering mortars and their painting layers are constantly exposed to weather and, therefore, influence the hygrothermal behavior of buildings. The characterization and assessment of coating materials is fundamental, seeking adequacy in their selection, especially regarding moisture and temperature. Considering the exposure conditions of the facades, risks of damages, such as mold development, may be avoided by an assertive evaluation and selection among different types of paints. In this context, this paper experimentally determined essential properties related to the hygrothermal behavior of painted mortars and simulated their resulting performance when applied on exposed facades in three Brazilian cities in distinct bioclimatic zones. Hygrothermal simulations were carried out using the software WUFI Pro 6.6. Six different types of paints were studied, among which satin acrylic paint (SAP) led to the lowest water vapor permeability and matte polyvinyl acetate (PVA), silicate (SIL), lime (LP), and hydrated lime with white glue (HLG) paints led to the highest. Matte acrylic paint (MAP), PVA, SIL, LP, and HLG had similar impacts on the vapor transmission of mortar renderings. In the simulations, reference (REF) and LP specimens generally resulted in the highest water contents throughout the year, followed by SIL and HLG. SAP led to the lowest water content and a more homogeneous curve than the other paints. Among the studied cities, Macapá, which has the highest annual normal rainfall sum and mean relative humidity, also had the highest mean total water content values over time, followed by Porto Alegre and Petrolina. In general, no probable mold development is expected. However, caution should be taken when extrapolating the results for climate or construction conditions different than the simulated ones. [ABSTRACT FROM AUTHOR]

Yttrium oxide is an ideal choice for titanium aluminum alloy melting and casting, its wider use is hindered by sintering challenges and low thermal shock resistance. To address this, we propose a gel casting method for calcium oxide-doped yttrium oxide production. We pretreated yttrium oxide with phosphoric acid to prevented hydrolysis and adjusted the isoelectric point of yttrium oxide to match calcium carbonate's. Anions from calcium carbonate increased slurry solid content (up to 58 vol%) while maintaining low viscosity (57.78 mPa·s at 40 s−1 shear rate). After sintering at 1650 °C for 2 h, the material showed a flexural strength of 78 MPa, with a 90% retention rate after thermal shock test. The introduction of calcium oxide induced lattice distortion, improving mechanical properties by aiding sintering and grain boundary diffusion. XPS and STEM analysis confirmed random replacement of Y3+ by Ca2+ at the C 2 position with 1 wt% doping. [ABSTRACT FROM AUTHOR]

The invasion of the colonial ascidian Didemnum vexillum (Kott, 2002) represents a significant threat to marine ecosystems. In Norway, D. vexillum was recorded for the first time in 2020 and has since continued spreading along the coast. Although the total eradication of this species appears highly unlikely, the implementation of control measures is important to slow down its proliferation and limit the impacts on important species and habitats. In this study, we performed three laboratory experiments, to separately test the effects of lime (fine and coarse quicklime particles and hydrated lime), hydrogen peroxide (H2O2; 0, 1000, 2000 and 4000 mg l-1) and Azamethiphos (0, 50, 100 and 200 µg l-1), on the biofouling cover of D. vexillum. No significant effect of Azamethiphos was detected on D. vexillum cover after 1 hr of exposure, while exposure to H2O2 for 1 hr only reduced its biofouling cover by 50% after exposure to the highest concentration (4000 mg l-1). Conversely, both fine and coarse quicklime particles appeared as suitable control options, reducing the size of the colonies by 100% and 99%, respectively, after exposure for 20 hrs. Additionally, treatment with hydrated lime induced a significant decline in D. vexillum cover by about 89% after 1 hr of exposure. Our results suggest the importance of considering the seasonal variations in environmental conditions and the biology of D. vexillum, to optimize the efficacy of the treatment. Here, we suggest using quicklime and hydrated lime between October and December in the Northern Hemisphere, to benefit from the natural degeneration of D. vexillum during winter and to more effectively eradicate potential remnants that could serve as a basis for regeneration. [ABSTRACT FROM AUTHOR]

Conventional techniques of soil stabilization involve using additives such as lime and cement. However, these methods take up a great deal of energy and cause considerable environmental pollution. Recently, bio-additives have been taken into account as sustainable development, cost-effective, and environmentally acceptable alternatives to chemical stabilizers in geo-environmental applications. In these techniques, bio-chemical activities, including bio-cementing, bio-clogging, bio-coating, and bio-encapsulation, are employed to stabilize soil particles. The present study aims to examine the impact of bio-stabilizers type and quantity on the geotechnical characteristics of soil for soil stabilization. For this purpose, the biochemical performance of various biological methods of soil stabilization (e.g., bio-microorganisms; bioenzymes; and biopolymers) is first presented. Then, the behaviors of bio-substances in all types of soils are investigated through a comprehensive review of previous research. Afterward, the biochemical behavior of bio-additives and their properties, mechanism, application, and interaction with soil particles are investigated on a microscopic and macroscopic scale. Next, the most effective factors in bio-stabilization are determined and evaluated. Finally, the essential recommendations for choosing the kinds and amount of bio-additives for soil stabilization are offered based on the soil type. The findings of this study indicate that the performance of bio-stabilizers is based on the percentage and type of bio-additives, soil type, and the quantity of electrostatic forces generated during cementation and hydrogel production. In addition, among various bio-additives, S. pasteurii and Bacillus sphaericus, TerraZyme, Xanthan gum, and Guar gum showed the best performance by increasing mechanical/shear strength by up to 300% and decreasing permeability, compressibility, and/or shrinkage properties. Furthermore, temperature, curing time, and soil pH were determined as crucial factors in establishing interlocking forces between soil particles and choosing the appropriate biomass. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study on the mechanical behavior of masonry specimens made from two brick types, factory-made and hand-made bricks, and three types of lime mortars, quicklime lumps, powdered hydrated lime, and commercial hydrated lime. The characteristics of the bricks and mortars and the interaction between each brick and mortar type were expected to have a significant effect on masonry strength. The results indicated that the compressive strength and specific surface area of the factory-made bricks were 15% greater and 22% lower, respectively, than those of hand-made bricks. Specifically, the factory-made bricks have a beneficial effect on specimens under compression, while hand-made bricks improve the specimen's shear strength. In addition, the commercial hydrated lime-based mortar exhibited the best bonding quality for both types of bricks [ABSTRACT FROM AUTHOR]

It is commonly known that mineral fillers significantly affect the asphalt mixture's performance. Superior flexible pavement performance can be ensured by gaining a deeper understanding of the function of filler. This research investigates the influence of three different fillers: granite dust, cement, and hydrated lime, at Australian asphalt mixtures. The testing program includes Marshall testing, moisture damage resistance, indirect tensile strength (ITS), and indirect tensile stiffness modulus (ITSM) tests of asphalt mixtures. Analysis of variance (ANOVA) was used to statistically assess the results obtained, besides damage analysis. The results indicate that using natural granite dust yields the highest resistance to moisture, while cement produces the highest stability, ITS, and ITSM. Unexpectedly, using hydrated lime filler decreases the stability/stiffness and moisture resistance of asphalt mixtures. ANOVA tests indicate that the type of filler affects ITS, TSR, and ITSM results (i.e., the p-value <0.05). The damage analysis shows that the design life of the asphalt mixture made with cement filler is higher than that of mixtures made with natural granite dust and hydrated lime fillers respectively. The findings indicate the important role of nontraditional fillers at the performance of Australian asphalt mixtures. [ABSTRACT FROM AUTHOR]

In order to study the effects of Al2O3 particle sizes on microstructure and properties of CA6 lightweight ceramic materials, lightweight calcium carbonate with an average particle size of 15 µm and α-Al2O3 with average particle sizes of 80, 61, 45 and 38 µm were used as calcium oxide and alumina sources, respectively. CA6 lightweight ceramic materials were prepared by foaming method combined with in-situ sintering technology after being heated at 1 550 °C for 5 h. Effects of Al2O3 starting materials with different particle sizes on their physical properties, phase composition and microstructure were investigated. The results show that with the decrease of α-Al2O3 particle size, the linear shrinkage, bulk density and thermal conductivity of CA6 lightweight ceramic materials gradually decreases, while their apparent porosity gradually increases and their compressive strength increases firstly and then decreases. Comprehensively considered, the specimen prepared by α-Al2O3 with an average particle size of 45 µm as alumina source has better comprehensive performance, and its apparent porosity, thermal conductivity and compressive strength are 87.8%, 0.149 W ⋅ m-1 ⋅ K-1 and 0.29 MPa, respectively, which can better meet the needs of application. [ABSTRACT FROM AUTHOR]

The alkali-activated composites technique is a promising method for the in situ preparation of cavity filling/grouting materials from engineering waste soil. To investigate the feasibility of engineering waste soil utilization by the alkali activation process, the macroscopic and microscopic properties of the fly ash/slag-based alkali-activated composites, after solidification/stabilization (S/S) with sandy clay excavated at Baishitang Station of Shenzhen Metro, were studied. The unconfined compressive strength (UCS) test was conducted to evaluate the S/S effect of alkali-activated composites. The results show that the optimum quality ratio of slag and fly ash correspond to 7:3, the modulus of alkaline activator to 1.3, and the alkalinity of alkaline activator to 10%. The alkali-activated composite's strength under these parameters can reach 45.25 MPa at 3 days, 49.85 MPa at 7 days, and 62.33 MPa at 28 days. A maximum 3-day UCS of 21.71 MPa, 75% of the 28-day UCS, was achieved by an engineering waste soil and alkali-activated composites mass ratio of 5:5, slaked lime content of 4.5%, and a water-to-solid ratio of 0.26, and it can also meet the required fluidity and setting time for construction well. Fluidity is primarily affected by the soil-to-binder ratio, which decreases as the ratio decreases, while the water-to-solid ratio increases fluidity. Slaked lime has minimal impact on fluidity. The setting time is mainly influenced by the soil-to-binder ratio, followed by slaked lime content and water-to-solid ratio, with setting time shortening as the soil-to-binder ratio and slaked lime content increase, and lengthening as the water-to-solid ratio increases. Through Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS) tests, microscopic analysis showed that loose granular units are firmly cemented by alkali-activated composites. Based on the results of on-site grouting tests in karst caves, the alkali-activated grout materials reached a strength of 5.2 MPa 28 days after filling, which is 162.5% of the strength of cement grouting material, satisfying most of the requirements for cavity filling in Shenzhen. [ABSTRACT FROM AUTHOR]

High-temperature Cr-Cr2Ta composites are promising candidates for replacing nickel-based precipitation-hardening superalloys for producing turbine blades. Segregation at the solidification of such alloys leads to a dendritic structure, which has a negative impact on the mechanical properties. In order to avoid such issues, powder metallurgy is considered a suitable method. In this work, the theoretical and practical aspects of producing Cr2Ta by powder metallurgy using metallothermic (calcium-hydride) synthesis of a refractory intermetallic compound from oxide raw materials have been studied. Using X-ray and electron microscopic analysis, it has been established that the formation of the Cr2Ta phase occurs due to solid-state diffusion of chromium particles in Ta. The apparent activation energy of this process is 291 ± 69 kJ/mol. It has been shown that the diffusion reaction actively occurs at a temperature of only 0.56 Tm of Cr2Ta. Thermodynamic calculations and thermal analysis have established that such a low temperature of formation of Cr2Ta is due to heat releasing during the exothermic reduction reaction of Cr2O3 oxide by calcium. The optimal synthesis parameters have been determined, and their influence on the phase composition of the powder has been studied. The developed technology makes it possible to obtain Cr2Ta intermetallic powder containing 95 ± 5 vol pct of the target phase, with a sponge particle morphology and a size of < 20 μm. Typical impurity content has been determined as follows: < 0.28 wt pct for oxygen, < 0.07 wt pct for nitrogen, and < 0.02 wt pct for hydrogen. Thus, the resulting powder can be used for the production of Cr-Cr2Ta composites. [ABSTRACT FROM AUTHOR]

The mechanical properties of Bituminous Stabilized Materials (BSMs) have been widely studied in the past, however the influence of temperature on their non-linear constitutive properties has never been addressed. In this research, the role of temperature on the mechanical properties of a BSM prepared with asphalt emulsion and hydrated lime was investigated. Triaxial shear strength tests were performed at different temperatures and confining pressures. The experimental results allowed the development of finite element models defining the local stress and temperature-dependent mechanical properties. An approach for incorporating plasticity and temperature effects through a 2D axisymmetric finite element model of multilayer pavement was developed. Three pavement structures were subjected to the same load applications at different temperatures. Their responses were compared to determine the most critical scenario. In conclusion, plasticity and temperature are key factors for BSMs analysis and design while linear-elastic assumptions lead to overestimating the service life of rehabilitated pavements. [ABSTRACT FROM AUTHOR]

The treatment of oily sludge by pyrolysis has the advantage of efficient recovery of pyrolysis tar, and it is an effective way to dispose oily sludge in a harmless and resourceful way. The high content of iron and calcium inorganic substances in oilfield sludge should not be neglected on the distribution of pyrolysis products and the removal of petroleum hydrocarbons. In this paper, the effects of iron and calcium oxides on the pyrolysis characteristics of oily sludge were investigated by using a fixed bed pyrolysis reactor to achieve the resourceful and harmless disposal of oily sludge, leading to the highest yield of liquid (15.97% and 17.60%) at 500 °C and the highest yield of gas (6.21% and 7.41%) at 700 °C pyrolysis of oily sludge. The addition of Fe2O3 not only increased CO and CO2 in the pyrolysis gas above 500 °C, but also increased the content of aromatic hydrocarbons in the pyrolysis tar. The presence of CaO not only promoted the formation of long-chain hydrocarbons in the pyrolysis tar, but also increased the percentage of H2, CH4 and C2H4 in the pyrolysis gas. By adding of Fe2O3 and CaO of 10% respectively at 500 °C, the content of petroleum hydrocarbons in the pyrolysis residue decreased to 1.87% and 1.94%, respectively. [ABSTRACT FROM AUTHOR]

Stacking compacted filtered tailings has become an option to cope with the new Brazilian regulations while providing a safe disposal method for the tailings. It has become feasible due to recent developments in dewatering technologies. Still, the dewatering processes may need to be improved to attain acceptable moisture contents considering the on-field compactable range. Also, the filtered material's moisture content is highly influenced by the weather conditions, especially during the rainy season in the southeast of Brazil. Additives are a possible solution to accelerate moisture reduction. However, scientific studies in the technical literature still need to attest to the effectiveness of these methods to tailings, mainly on a full scale. Accordingly, the present research evaluates the performance of two additives to hasten filtered iron ore tailings drying for dry stacking purposes: commercially available quicklime and superabsorbent polymer. Also, undrained triaxial tests were conducted on specimens retrieved from on-field compacted layers to investigate the additive's influence on the tailings' mechanical behaviour. Initial confining pressures ranging from 100 to 600 kPa were used. The results have shown the inefficacy of the superabsorbent additives in boosting the drying process for on-field conditions and the efficiency of the quicklime in doing so. Furthermore, no substantial changes in the mechanical response were observed due to the insertion of quicklime. This highlights the novelty of the present study in the context of iron ore tailings management. [ABSTRACT FROM AUTHOR]

Diversifying cultivation management, including different crop rotation patterns and soil amendment, are effective strategies for alleviating the obstacles of continuous cropping in peanut (Arachis hypogaea L.). However, the peanut yield enhancement effect and temporal changes in soil chemical properties and microbial activities in response to differential multi-year crop rotation patterns and soil amendment remain unclear. In the present study, a multi-year localization experiment with the consecutive application of five different cultivation managements (including rotation with different crops under the presence or absence of external quicklime as soil amendment) was conducted to investigate the dynamic changes in peanut nutrient uptake and yield status, soil chemical property, microbial community composition and function. Peanut continuous cropping led to a reduction in peanut yield, while green manure-peanut rotation and wheat-maize-peanut rotation increased peanut yield by 40.59 and 81.95%, respectively. A combination of quicklime application increased yield by a further 28.76 and 24.34%. Alterations in cultivation management also strongly affected the soil pH, nutrient content, and composition and function of the microbial community. The fungal community was more sensitive than the bacterial community to cultivation pattern shift. Variation in bacterial community was mainly attributed to soil organic carbon, pH and calcium content, while variation in fungal community was more closely related to soil phosphorus content. Wheat-maize-peanut rotation combined with quicklime application effectively modifies the soil acidification environment, improves the soil fertility, reshapes the composition of beneficial and harmful microbial communities, thereby improving soil health, promoting peanut development, and alleviating peanut continuous cropping obstacles. We concluded that wheatmaize-peanut rotation in combination with quicklime application was the effective practice to improve the soil fertility and change the composition of potentially beneficial and pathogenic microbial communities in the soil, which is strongly beneficial for building a healthy soil micro-ecology, promoting the growth and development of peanut, and reducing the harm caused by continuous cropping obstacles to peanut. [ABSTRACT FROM AUTHOR]

Red mud (RM) is an industrial waste generated in the process of aluminum refinement. The recycling and reusing of RM have become urgent problems to be solved. To explore the feasibility of using RM in geotechnical engineering, this study combined magnesium oxide (MgO) (or calcium oxide (CaO)) with RM as an RM-based binder, which was then used to stabilize the soil. The physical, mechanical, and micro-structural properties of the stabilized soil were investigated. As the content of MgO or CaO in the mixture increased, the unconfined compressive strength (UCS) of the RM-based cementitious materials first increased and then decreased. For the soils stabilized with RM–MgO or RM–CaO, the UCS increased and then decreased, reaching a maximum at RM:MgO = 5:5 or RM:CaO = 8:2. The addition of sodium hydroxide (NaOH) promoted the hydration reaction. The UCS enhancement ranged from 8.09% to 66.67% for the RM–MgO stabilized soils and 204.6% to 346.6% for the RM–CaO stabilized soils. The optimum ratio of the RM–MgO stabilized soil (with NaOH) was 2:8, while that of the RM–CaO stabilized soil (with NaOH) was 4:6. Freeze–thaw cycles reduced the UCS of the stabilized soil, but the resistance of the stabilized soil to freeze–thaw erosion was significantly improved by the addition of RM–MgO or RM–CaO, and the soil stabilized with RM–MgO had better freeze–thaw resistance than that with RM–CaO. The hydrated magnesium silicate generated by the RM–MgO stabilized soil and the hydrated calcium silicate generated by the RM–CaO stabilized soil helped to improve the UCS of the stabilized soil. The freeze–thaw cycles did not weaken the formation of hydration products in the stabilized soil but could result in physical damage to the stabilized soils. The decrease in the UCS of the stabilized soil was mainly due to physical damage. [ABSTRACT FROM AUTHOR]

In order to increase the utilization rate of stainless steel slag, reduce storage needs, and mitigate environmental impacts, this study replaces a portion of limestone with varying amounts of stainless steel slag in the calcination of Portland cement clinker. The study primarily examines the influence of stainless steel slag on the phase composition, microstructure, compressive strength, and free calcium oxide (ƒ-CaO) content of Portland cement clinker. The results show the following: (1) Using stainless steel slag to calcine Portland cement clinker can lower the calcination temperature, reducing industrial production costs and energy consumption. (2) With an increase in the amount of stainless steel slag, the dicalcium silicate (C2S) and tricalcium silicate (C3S) phases in Portland cement clinker initially increase and then decrease; the C3S crystals gradually transform into continuous hexagonal plate-shaped distributions, while the tricalcium aluminate (C3A) and tetracalcium aluminoferrite (C4AF) crystal structures become denser. When the stainless steel slag content is 15%, the dicalcium silicate and tricalcium silicate phases are at their peak; the C3S crystals are continuously distributed with a relatively dense structure, and C3A and C4AF crystals melt and sinter together, becoming distributed around C3S. (3) As stainless steel slag content increases, the compressive strength of Portland cement clinker at 3 days, 7 days, and 28 days increases and then decreases, while ƒ-CaO content decreases and then increases. When the stainless steel slag content is 15%, the compressive strength at 28 days is at its highest, 64.4 MPa, with the lowest ƒ-CaO content, 0.78%. The test results provide a basis for the utilization of stainless steel slag in the calcination of Portland cement clinker. [ABSTRACT FROM AUTHOR]

The unique properties of calcium oxide (CaO) and zinc oxide (ZnO) at the nanoscale have attracted the interest of scientists as promising electrically conductive substances for sensing purposes. The content of terbinafine hydrochloride (TRF) in pharmaceutical tablets was determined using a novel coated, wire‐functionalized CaO/ZnO nanocomposite membrane sensor biogenically produced from Lavandula spica extract. Sodium tetraphenylborate was used to prepare the active material (TRF‐TBP). The newly modified sensor gave excellent potentiometric sensitivity with the least squares regression equation EmV=(−58.88X±0.3)+log [TRF]+549.78 and covered a wide linear range (5.0×10−9–1.0×10−2 mol/L) of TRF samples. In contrast, the standard TRF‐TBP sensor wasn't as sensitive when (2.5×10−6–1.0×10−2 mol/L). TRF solutions with regression equation of (−55.728X±0.7)+log [TRF]+396.64. The appropriate pH range was 3–6. The principles of analytical methodology were applied to investigate the validity and suitability of the proposed technique. The proposed sensors were found to be suitable and efficient for the detection of TRF on tablets. [ABSTRACT FROM AUTHOR]