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Purpose: The purpose of this study is to improve the mechanical property and processing performance and reduce the cost of the polylacticacid/polybutyleneadipate-co-terephthalate(PLA/PBAT) composites, the calcium carbonate (CaCO3) and compatibilizer styrene-maleicanhydride copolymer (SMA-2025) were added to the PLA/PBAT system, and the effect of CaCO3 and SMA-2025 on the morphology, structure, mechanical property, thermal property, thermalstability and shape memory property of the CaCO3/PLA/PBAT composites were studied and discussed. Design/methodology/approach: The CaCO3/PLA/PBAT shape memory composites were prepared via melt-blending and hot-pressing methods, and the effect of CaCO3 and SMA-2025 on the property of the composites was investigated via scanning electron microscope, universal testing instrument, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis and DMA, respectively. Findings: The interface property, mechanical property, thermal stability, shape memory recovery ratios and recovery stresses, and processing performance of the CaCO3/PLA/PBAT shape memory composites were significantly improved by adding of CaCO3 and SMA-2025. Moreover, the CaCO3/PLA/PBAT composites have good blowing film processing performance. Originality/value: This study will provide a reference for the research, processing and application of the high-performance CaCO3/PLA/PBAT shape memory composites. [ABSTRACT FROM AUTHOR]

Coral skeletal B/Ca (effectively B/CO 3 2–), in combination with boron isotopic composition (δ11B), has been used to reconstruct the dissolved inorganic carbon chemistry of coral calcification media and to explore the biomineralisation process and its response to ocean acidification. This approach assumes that B(OH) 4 −, the B species incorporated into aragonite, competes with dissolved inorganic carbon species for inclusion in the mineral lattice. In this study we precipitated aragonite from seawater in vitro under conditions that simulate the compositions of the calcification media used to build tropical coral skeletons. To deconvolve the effects of pH and [CO 3 2–] on boron incorporation we conducted multiple experiments at constant [CO 3 2–] but variable pH and at constant pH but variable [CO 3 2–], both in the absence and presence of common coral skeletal amino acids. Large changes in solution [CO 3 2–], from < 400 to >1000 µmol kg−1, or in precipitation rate, have no significant effect on aragonite B/Ca at pH total of 8.20 and 8.41. A significant inverse relationship is observed between solution [CO 3 2–] and aragonite B/Ca at pH total = 8.59. Aragonite B/Ca is positively correlated with seawater pH across precipitations conducted at multiple pH but this relationship is driven by the effect of pH on the abundance of B(OH) 4 – in seawater. Glutamic acid and glycine enhance the incorporation of B in aragonite but aspartic acid has no measurable effect. Normalising aragonite B/Ca to solution [B(OH) 4 –] creates K D B(OH)4− which do not vary significantly between pH treatments. This implies that B(OH) 4 – and CO 3 2– do not compete with each other for inclusion in the aragonite lattice at pH total 8.20 and 8.41. Only at high pH (8.59), when [B(OH) 4 –] is high, do we observe evidence to suggest that the 2 anions compete to be incorporated into the lattice. These high pH conditions represent the uppermost limits reliably measured in the calcification media of tropical corals cultured under present day conditions, suggesting that skeletal B/Ca may not reflect the calcification media dissolved inorganic carbon chemistry in all modern day corals. [ABSTRACT FROM AUTHOR]

The K3LuSi2O7 phosphor doping Eu2+ rare-earth ions (KLS:Eu) was reported to possess broad emission band from near-ultraviolet to nearinfrared. Additionally, this phosphor showed a wide absorption band of 250-600 nm, allowing it to be excited by blue-light chip of 460 nm, making it one of the suitable phosphor materials for a light emitting diode (LED). Besides, the scattering particle material CaCO3 is incorporated into the yellow phosphor layer to serve the scattering-enhancement purpose. The combination of both materials aims at accomplishing improvements in performance of commercial LED package. The concentration of KLS:Eu is constant while that of CaCO3 is modified. As a result, the scattering factor is regulated and become the key factor influencing the optical outputs of the simulated LED. The increasing CaCO3 concentration enhances the phosphor scattering efficiency of light, helping to improve the lumen output and colortemperature consistency of the LED. However, the color rendering performance declines as a function of the CaCO3 growing amount, despite the presence of a KLS:Eu phosphor layer. Further works should be done to optimize the application of KLS:Eu in cooperation with scattering particles for a higher-quality LED device. [ABSTRACT FROM AUTHOR]

We investigated the impact of CaCO3 addition on the density and compressive strength of calcium aluminate cement (CAC)-based cementitious materials in binder jetting additive manufacturing (BJAM). To confirm the formation of a uniform powder bed, we examined the powder flowability and powder bed density for CaCO3 contents ranging from 0 to 20 wt.%. Specifically, powders with avalanche angles between 40.1–45.6° formed a uniform powder bed density with a standard deviation within 1%. Thus, a 3D printing specimen (green body) fabricated via BJAM exhibited dimensional accuracy of less than 1% across the entire plane. Additionally, we measured the hydration characteristics of CAC and the changes in compressive strength over 30 days with the addition of CaCO3. The results indicate that the addition of CaCO3 to CAC-based cementitious materials forms multimodal powders that enhance the density of both the powder bed and the green body. Furthermore, CaCO3 promotes the formation of highly crystalline monocarbonate (C4AcH11) and stable hydrate (C3AH6), effectively inhibiting the conversion of CAC and showing compressive strengths of up to 5.2 MPa. These findings suggest a strong potential for expanding the use of BJAM across various applications, including complex casting molds, cores, catalyst supports, and functional architectural interiors. [ABSTRACT FROM AUTHOR]

Background: Currently, tap water consumption is not highly preferred in Egypt and around the world. People prefer to consume bottled water because they believe that it is much safer and tastes better than tap water. Unfortunately, this preference can create an economic burden for many people, especially in developing countries. Clay pots can be used to provide cool, alkaline drinking water because of their porous micro-texture, which traps pollutants. This study aimed to investigate the use of clay pots to store tap water and its impact on the requirements for drinking water quality. This is done with the intent to decrease the need for bottled water as a means of offering a more sustainable and economical option. Methods: In this study, the efficiency of clay pots as sustainable storage containers for drinking water was tested by measuring physicochemical parameters (pH, TDS, EC, turbidity, DO, ammonia, chloride, total hardness, Ca hardness, Mg hardness, chlorine, Zn, and CaCO3) and biological parameters (TPC and Legionella). Results: After 7 days of storage, the quality of the water stored in clay pots met the standards set by the Egyptian law with a significant difference (p < 0.05) before and after the storage of water It was found that the dissolved oxygen increased from 6.17 ppm to 7.52 ppm after 7 days. As for total hardness, it declined from 195 to 178 ppm. There was also a significant drop in terms of TDS from 338 to 275 ppm. Furthermore, clay pots effectively filtered out both total viable bacteria and Legionella. Conclusion: This study proved the efficiency of using these containers with respect to some indicator values for tap water and tank water analysis. Clay pots are an excellent, cost-effective, and sustainable alternative for storing water. [ABSTRACT FROM AUTHOR]

Because of its high specific capacity and superior rate performance, porous carbon is regarded as a potential anode material for lithium‐ion batteries (LIBs). However, porous carbon materials with wide pore diameter distributions suffer from low structural stability and low electrical conductivity during the application process. During this study, the calcium carbonate nanoparticle template method is used to prepare coal tar pitch‐derived porous carbon (CTP−X). The coal tar pitch‐derived porous carbon has a well‐developed macroporous‐mesoporous‐microporous hierarchical porous network structure, which provides abundant active sites for Li+ storage, significantly reduces polarization and charge transfer resistance, shortens the diffusion path and promotes the rapid transport of Li+. More specifically, the CTP‐2 anode shows high charge capacity (496.9 mAh g−1 at 50 mA g−1), excellent rate performance (413.6 mAh g−1 even at 500 mA g−1), and high cycling stability (capacity retention rate of about 100 % after 1,000 cycles at 2 A g−1). The clean and eco‐friendly large‐scale utilization of coal tar pitch will facilitate the development of high‐performance anodes in the field of LIBs. [ABSTRACT FROM AUTHOR]

Abstract Background Currently, tap water consumption is not highly preferred in Egypt and around the world. People prefer to consume bottled water because they believe that it is much safer and tastes better than tap water. Unfortunately, this preference can create an economic burden for many people, especially in developing countries. Clay pots can be used to provide cool, alkaline drinking water because of their porous micro-texture, which traps pollutants. This study aimed to investigate the use of clay pots to store tap water and its impact on the requirements for drinking water quality. This is done with the intent to decrease the need for bottled water as a means of offering a more sustainable and economical option. Methods In this study, the efficiency of clay pots as sustainable storage containers for drinking water was tested by measuring physicochemical parameters (pH, TDS, EC, turbidity, DO, ammonia, chloride, total hardness, Ca hardness, Mg hardness, chlorine, Zn, and CaCO3) and biological parameters (TPC and Legionella). Results After 7 days of storage, the quality of the water stored in clay pots met the standards set by the Egyptian law with a significant difference (p

CaCO3 has long been used as a filler to increase many properties of the material. The filler commonly consists of inexpensive materials that replace some volume of the more expensive materials, which can reduce the cost of the final product. CaCO3 morphology that can be used as filler depends on the filler's function, such as filler for paper, paint, rubber, or composite. A filler for composite materials is needed to increase interfacing interactions between the particulate fillers and the matrix. So, the particulate in a broader shape will be the best choice to function for such filler. In this research, in an attempt to increase the interfacing interaction, CaCO3 morphology was modified in such a way through crystal lattice modification assisted by sulfate incorporation and vibration. SEM analysis was implemented, and showed that the research successfully produced novel morphology in branchy-like polymorphs. FTIR analysis also proved that the crystal lattice has been modified. The morphology in branchy-like polymorph is supposed to increase interfacing interaction between CaCO3 as the filler and the matrix. The methods are also supposed to be implemented as the research is scaled up to commercial scale.

During intervertebral disc (IVD) degeneration, microenvironmental challenges such as decreasing levels of glucose, oxygen, and pH play crucial roles in cell survival and matrix turnover. Antacids, such as Mg(OH)2 and CaCO3, entrapped in microcapsules are capable of neutralizing acidic microenvironments in a controlled fashion and therefore may offer the potential to improve the acidic niche of the degenerated IVD and enhance cell‐based regeneration strategies. The objectives of this work were, first, to develop and characterize antacid microcapsules and assess their neutralization capacity in an acidic microenvironment and, second, to combine antacid microcapsules with cellular microcapsules in a hybrid gel system to investigate their neutralization effect as a potential therapeutic in a disc explant model. To achieve this, we screened five different pH‐ neutralizing agents (Al(OH)3, Mg(OH)2, CaCO3, and HEPES) in terms of their pH neutralization capacities, with Mg(OH)2 or CaCO3 being carried forward for further investigation. Antacid‐alginate microcapsules were formed at different concentrations using the electrohydrodynamic spraying process and assessed in terms of size, buffering kinetics, cell compatibility, and cytotoxicity. Finally, the combination of cellular microcapsules and antacid capsules was examined in a bovine disc explant model under physiological degenerative conditions. Overall, CaCO3 was found to be superior in terms of neutralization capacities, release kinetics, and cellular response. Specifically, CaCO3 elevated the acidic pH to neutral levels and is estimated to be maintained for several weeks based on Ca2+ release. Using a disc explant model, it was demonstrated that CaCO3 microcapsules were capable of increasing the local pH within the core of a hybrid cellular gel system. This work highlights the potential of antacid microcapsules to positively alter the challenging acidic microenvironment conditions typically observed in degenerative disc disease, which may be used in conjunction with cell therapies to augment regeneration. [ABSTRACT FROM AUTHOR]

Wear on a metal can be naturally found in components that operate in a friction environment, such as in a transmission system. However, it can be a substantial problem when the wear rate is not within the permitted limit. Surface hardening is a popular way to improve surface wear resistance for metals with various parameters that can be controlled during the process. In this study, pack carburizing was conducted for plain carbon steel JIS S45C. The carburizing process is conducted on the steel by varying the carbon size and temperature during the heating process. The carbon size consisted of mesh sizes of 5 and 15. The heating process was conducted for 2 hours at 800oC and 900oC. The carbon media and catalyst used in this study were coconut charcoal and calcium carbonate (CaCO3). In addition, the hardness Vickers test was conducted to evaluate the surface hardness. It was found that the hardness of Vickers increased with an increase in heating temperature and mesh size of carbon.

Abstract The current experimental work aimed at developing PCC through two major process steps: dissolution and precipitation, using raw materials domestically available as SL, which are intensively used in construction inputs. The pH level was the decisive parameter used to determine the time required to complete the dissolution and carbonation processes during precipitation. The optimal pH levels were found to be 13 for dissolution and 7.1 for precipitation, respectively. The produced PCC was characterized based on chemical analysis, crystallinity, and morphology, showing an increment of CaCO3 content exceeding 99%, sharper crystal peaks, and predominantly calcite PCC. The compatibility of the PCC was assessed by incorporating 25%, 50%, 75%, and 100% of PCC with commercial filler, followed by selected mechanical tests, such as stress at yield, density, and elongation at break. The results indicated that mixing ratios of 25%, 50%, and 75% of PCC with the commercial filler met the standards, with stress at a yield above 45 MPa and density within the range of 1.35 to 1.46 g/cm3. However, complete substitution slightly lowered these properties. Nevertheless, the elongation at break was acceptable at all treatment levels.

Grain refinement is a crucial technique for enhancing the mechanical properties and corrosion resistance of magnesium alloys. In this study, the addition of 0.3 wt% CaO and 0.3 wt% CaCO3 successfully refined the AM60 alloy, resulting in a significant reduction in the average grain size from 326 μm to 96 μm (when adding CaCO3). The refined grain size of the as-cast AM60 alloy led to an increase in both tensile strength and yield strength to 118.2 MPa and 72.6 MPa, representing a respective increase of 35% and 23% compared to the alloy without the refiner. As results of EBSD, it is verified that the basal slip system (0001) has a higher Schmid factor after adding CaO, which indicates that this system has higher activity. The substitution reaction between CaO and Mg can produce synergistic effects from the solute effect of Ca and the nucleating effect of residual CaO, which play an important role in grain refinement. Due to the fine grain size and diffuse distribution of the second phase in the AM60-CaCO3 alloy and the thermal decomposition of CaCO3, which consumes the aluminum element in the matrix, the content of the β-phase (Mg17Al12) is reduced. Consequently, this reduces the electric coupling effect between the β-phase and the magnesium matrix. The AM60-CaCO3 alloy exhibited the most superior corrosion resistance, achieving a corrosion rate of only 1.01 mm y−1, representing a 48.9% reduction in corrosion rate compared to the AM60 alloy.

In this work, isotactic polypropylene (iPP) was modified with an organic phosphate salt nucleating agent LPN-9081 and CaCO3. The synergistic effect of LNP-9801 and CaCO3 in iPP was investigated using differential scanning calorimetry (DSC), scanning electronic microscope (SEM), and mechanical property tests. The DSC results showed that the peak crystallization temperature (Tc) of modified iPP was increased by about 10 °C when compared to that of pure iPP, this indicates that LNP-9801 and CaCO3 increased the crystallization rate of iPP. The mechanical property tests demonstrated significant improvements in bending modulus and impact strength of modified iPP (impact strength increased by 33.9%, flexural modulus increased by 100.1%), which achieved an optimal balance of stiffness and toughness. Furthermore, the SEM results indicated that LPN-9081 contributed to the good dispersion of CaCO3 in the iPP matrix. All of the above results show that organic phosphate salt nucleating agent LPN-9081 and CaCO3 had good synergistic effects in iPP. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) is a bio ceramic commonly utilized in bone tissue engineering due to its bioactive and osteoconductive properties. Crab shells are usually disregarded as waste material despite their significant CaCO3 content, and have not been widely utilized in the synthesis of HA. This study aims to synthesize and analyze HA derived from crab shells using the hydrothermal method with different durations of holding time. This study utilized precipitated calcium carbonate (PCC) derived from crab shells. With a hydrothermal reactor set at 160°C and varying holding times of 14 (HA_14), 16 (HA_16), and 18 (HA_18) h, a PCC and (NH4)2HPO4 mixture was used to synthesize HA. The synthesis results were analyzed using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) tests. This study has accomplished the synthesis of HA from crab shells. Nonetheless, the final product of synthesis still contained CaCO3 as an impurity. The prolonged hydrothermal holding time of 14 to 18 h resulted in a reduction of impurities while increasing the percentage of crystal weight and crystallite size of HA. Specimen CH_18 is the best-quality product generated in this study. This specimen produced HA with the highest percentage of crystal weight and crystallite size compared to the other specimens. Furthermore, specimen CH_18 exhibited the lowest concentration of impurities. The Ca/P ratio in this specimen was also the closest to 1.67. The Ca/P ratio, crystallite size, and crystal weight percentage of this specimen are 1.54, 19.06 nm, and 99.1%, respectively. [ABSTRACT FROM AUTHOR]

The excess presence of calcium carbonate (CaCO3) in soil poses challenges for production of horticultural crops, including tomatoes. This condition is prevalent in arid and semi-arid regions of Afghanistan. The objective of this study was to evaluate the effects of elevated concentrations of CaCO3 on growth, physiology, and quality attributes of tomato. Seedlings were exposed to different concentrations of CaCO3 (0%, 2.5%, 5%, 10%, and 20% w/w) in soil. The results showed that elevated concentrations of CaCO3 (10% and 20%) significantly increased soil electrical conductivity (EC) and pH, and subsequently affected growth, physiology, and quality of tomato. CaCO3 effects resulted in an increase in leaf electrolyte leakage, leaf calcium content, root respiration rate, root ethylene production, fruit firmness, total soluble solids, ascorbic acid, and organic acids, as well as a decrease in plant height, leaf length, leaf magnesium content, leaf SPAD value, number of leaves per plant, root weight and length, and root activity. At higher concentrations, CaCO3 decreased number of flowers and fruit per plant, as well as fruit weight and diameter, consequently affecting yield production. Although elevated concentrations of CaCO3 is characteristic of soils in Afghanistan, limited information is available about this topic. These findings enhance our understanding of soil conditions in the country and provide valuable insights for farmers. [ABSTRACT FROM AUTHOR]

The current experimental work aimed at developing PCC through two major process steps: dissolution and precipitation, using raw materials domestically available as SL, which are intensively used in construction inputs. The pH level was the decisive parameter used to determine the time required to complete the dissolution and carbonation processes during precipitation. The optimal pH levels were found to be 13 for dissolution and 7.1 for precipitation, respectively. The produced PCC was characterized based on chemical analysis, crystallinity, and morphology, showing an increment of CaCO3 content exceeding 99%, sharper crystal peaks, and predominantly calcite PCC. The compatibility of the PCC was assessed by incorporating 25%, 50%, 75%, and 100% of PCC with commercial filler, followed by selected mechanical tests, such as stress at yield, density, and elongation at break. The results indicated that mixing ratios of 25%, 50%, and 75% of PCC with the commercial filler met the standards, with stress at a yield above 45 MPa and density within the range of 1.35 to 1.46 g/cm3. However, complete substitution slightly lowered these properties. Nevertheless, the elongation at break was acceptable at all treatment levels. [ABSTRACT FROM AUTHOR]

Deploying energy storage and carbon capture at scale is hindered by the substantial endothermic penalty of decomposing CaCO3 to CaO and CO2, and the rapid loss of CO2 absorption capacity by CaO sorbent particles due to sintering at the high requisite decomposition temperatures. The decomposition reaction mechanism underlying sorbent deactivation remains unclear at the atomic level and nanoscale due to past reliance on postmortem characterization methods with insufficient spatial and temporal resolution. Thus, elucidating the important CaCO3 decomposition reaction pathway requires direct observation by time‐resolved (sub‐)nanoscale methods. Here, chemical and structural dynamics during the decomposition of CaCO3 nanoparticles to nanoporous CaO particles comprising high‐surface‐area CaO nanocrystallites are examined. Comparing in situ transmission electron microscopy (TEM) and synchrotron X‐ray diffraction experiments gives key insights into the dynamics of nanoparticle calcination, involving anisotropic CaCO3 thermal distortion before conversion to thermally dilated energetically stable CaO crystallites. Time‐resolved TEM uncovered a novel CaO formation mechanism involving heterogeneous nucleation at extended CaCO3 defects followed by sweeping reaction front motion across the initial CaCO3 particle. These observations clarify longstanding, yet incomplete, reaction mechanisms and kinetic models lacking accurate information about (sub‐)nanoscale dynamics, while also demonstrating calcination of CaCO3 without sintering through rapid heating and precise temperature control. [ABSTRACT FROM AUTHOR]

In many industries, calcium carbonate (CaCO3) and titanium dioxide (TiO2) are popular fillers and pigments. However, its application in a nonpolar medium is limited due to its surface characteristics in pristine conditions. This study focuses on modifying CaCO3 and TiO2 nanoparticles using oleic and stearic acid. Several characterizations were performed to assess the changes in the treated material, including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, scanning electron microscopy, as well as energy dispersive X-ray spectroscopy. Additionally, the dispersion stability of both materials in different nonpolar solvents was visually inspected. The interaction of materials in surface modifications is a success where few additional peaks were presented in FTIR spectroscopy. The morphology and sedimentation outcomes revealed that the treated materials induced a better dispersion, smoother surface, and higher stability. The improvements in treated materials indicate a successful modification of the CaCO3 and TiO2 nanoparticles for nonpolar medium applications. [ABSTRACT FROM AUTHOR]

Freshwater lobsters are one of the crustacean commodities that have started to be developed through cultivation. Besides having high nutritional value, freshwater lobsters have a stable sales value or price throughout the year. Freshwater lobster is a crustacean commodity that is not easily stressed or easily attacked by disease. The availability of calcium is essential for lobster growth, especially the formation of its shell. This research aims to determine the effectiveness of adding calcium carbonate at different time intervals by adding 150 mg/L CaCo3 lime. The study was conducted from June to July 2020 at the Aquaculture Environmental Laboratory, Bogor Agricultural Institute. The research used a Completely Randomized Design (CRD) with five treatments and three replications. The treatment used was K+ and K-, and the time interval for adding CaCo3 was once every five days, once every ten days, and once every 15 days. The aquarium measures 100 x 50 x 51 cm with a water height of 21 cm. The lobster used measures 1.5 cm. The research results after statistical testing showed that aquarium A1 (addition of CaCo3 every five days) experienced an increase in length of 0.67 cm. Weight of 0.67 g, B1 (addition of CaCo3 every ten days) experienced an increase in length of 0.87 cm and weight of 0.78 g, C1 (addition of CaCo3 every 15 days) experienced an increase in length of 0.97 cm and weight of 0.98 g, K+1 experienced an increase in length of 1.05 cm and weight of 1.06 gr, K-1 experienced an increase in length of 0.46 cm and weight of 0.45 g. [ABSTRACT FROM AUTHOR]

The coral reef ecosystem is one of the most productive ecosystems in the ocean, and is also an important calcium carbonate deposition region. Because excess production is very low in coral reefs, organic carbon reservoirs are very limited. During the calcification process, each mole of CaCO3 will produce 1 mol of CO2, approximately 60% of which will be released into the atmosphere through the sea-air interface. This causes coral reefs to be large inorganic carbon reservoirs, but at the same time, most coral reefs act as atmospheric CO2 sources (which also act as sinks in some coral reefs). Therefore, clarifying the sea-air CO2 exchange flux and carbon storage is critical for understanding the carbon cycle in coral reef ecosystems. In this paper, we summarize the carbon cycle processes in the coral reefs of the South China Sea (SCS) and estimate the total CO2 budget and carbon reserves. According to current research, the coral reefs in this area act as a source of atmospheric CO2, releasing 0.37−1.59 × 1011 g C a-1 into the atmosphere. Owing to their extremely high biological productivity and carbonate productivity, the carbon reserves of coral reefs in the SCS range from 1.66–3.78 × 1012 g C a-1, which is an order of magnitude greater than the CO2 emissions at the sea–air interface. Overall, coral reefs in the SCS are important carbon storage areas. As the current results are still approximate, a more comprehensive and in-depth investigation is needed to clarify the carbon source/sink processes, regulatory mechanisms, and carbon storage capacity of SCS coral reefs.

Abstract Cement is the most widely used construction material due to its strength and affordability, but its production is energy intensive. Thus, the need to replace cement with widely available waste material such as incinerated black filter cake (IBFC) in order to reduce energy consumption and the associated CO2 emissions. However, because IBFC is a newly discovered cement replacement material, several parameters affecting the mechanical properties of IBFC-cement composite have not been thoroughly investigated yet. Thus, this work aims to investigate the impact of IBFC as a cement replacement and the addition of the calcifying bacterium Lysinibacillus sp. WH on the mechanical and self-healing properties of IBFC cement pastes. The properties of the IBFC-cement pastes were assessed by determining compressive strength, permeable void, water absorption, cement hydration product, and self-healing property. Increases in IBFC replacement reduced the durability of the cement pastes. The addition of the strain WH to IBFC cement pastes, resulting in biocement, increased the strength of the IBFC-cement composite. A 20% IBFC cement-replacement was determined to be the ideal ratio for producing biocement in this study, with a lower void percentage and water absorption value. Adding strain WH decreases pore sizes, densifies the matrix in ≤ 20% IBFC biocement, and enhances the formation of calcium silicate hydrate (C–S–H) and AFm ettringite phases. Biogenic CaCO3 and C–S–H significantly increase IBFC composite strength, especially at ≤ 20% IBFC replacement. Moreover, IBFC-cement composites with strain WH exhibit self-healing properties, with bacteria precipitating CaCO3 crystals to bridge cracks within two weeks. Overall, this work provides an approach to produce a "green/sustainable" cement using biologically enabled self-healing characteristics.

We studied changes in the concentrations of aggregate-cementing agents after different reclamation times and with different fertilization regimes, as well as the formation mechanism of aggregates in reclaimed soil, to provide a theoretical basis for rapid reclamation of soil fertility in the subsidence area of coal mines in Shanxi Province, China. In this study, soil samples of 0–20 cm depth were collected from four fertilization treatments of a long-term experiment started in 2008: no fertilizer (CK), inorganic fertilizer (NPK), chicken manure compost (M), and 50% inorganic fertilizer plus 50% chicken manure compost (MNPK). The concentrations of cementing agents and changes in soil aggregate size distribution and stability were analysed. The results showed that the formation of >2 mm aggregates, the aggregate mean weight diameter (MWD), and the proportion of >0.25 mm water-stable aggregates (WR0.25) increased significantly after 6 and 11 years of reclamation. The concentration of organic cementing agents tended to increase with reclamation time, whereas free iron oxide (Fed) and free aluminium oxide (Ald) concentrations initially increased but then decreased. In general, the MNPK treatment significantly increased the concentrations of organic cementing agents and CaCO3, and CaCO3 increased by 60.4% at 11 years after reclamation. Additionally, CaCO3 had the greatest effect on the stability of aggregates, promoting the formation of >0.25 mm aggregates and accounting for 54.4% of the variance in the proportion and stability of the aggregates. It was concluded that long-term reclamation is beneficial for improving soil structure. The MNPK treatment was the most effective measure for increasing maize grain yield and concentration of organic cementing agents and CaCO3.

Polypropylene (PP) is a strong, tough, crystalline thermoplastic material with high performance. Because of its diverse thermo-physical and mechanical properties, it is utilized in a wide variety of disciplines. In this study, the impact of free quenching on the thermo-physical characteristics of PP/calcium carbonate (CaCO3) composites was examined. Three distinct heating procedures were used. First, composites were cooled from their melting phase temperature to ambient temperature. Second, composites were cooled from 130°C to a pre-determined and controlled temperature (T: 0°, 20°, 30°, 40°, 50°, 60°, 70°, 80°C). Third, composites were temperature-tested using annealing. The findings suggest that the elongation-at-break and impact strength may be improved following an initial quenching process from the melting phase to ambient temperature. On the other hand, a second quenching process at 0°C produces superior results, and a correlation between mechanical and thermal characteristics is noted; however, while these qualities are increased, others, such as flexibility, density, Vicat softening temperature (VST), and heat distortion temperature (HDT) are negatively impacted.

Patchy interactions and heterogeneous charge distribution make nanoclay (NC) a promising biomaterial to interact with different biomolecules, polymers, and biological components. Many researchers have studied the polymer/clay nanocomposites in recent years. However, some deficiencies, such as poor impact strength, limit the application of polymer/clay nanocomposites in different fields. As a result, many attempts have been made to resolve this problem. Also, researchers have developed calcium carbonate (CaCO3) nanoparticles as biomedical materials. The nontoxic properties and biocompatibility of both CaCO3 and NC make their nanocomposites ideal for biomedical applications. In this article, a detailed review of the ternary polymer nanocomposites containing NC and CaCO3 is presented. The morphological, thermal, mechanical, and rheological characteristics, in addition to the modeling of behavior and foam properties, are studied in this article. In addition, the potential challenges for ternary nanocomposites and their biomedical applications are discussed.

Polypropylene (PP) is a strong, tough, crystalline thermoplastic material with high performance. Because of its diverse thermo-physical and mechanical properties, it is utilized in a wide variety of disciplines. In this study, the impact of free quenching on the thermo-physical characteristics of PP/calcium carbonate (CaCO3) composites was examined. Three distinct heating procedures were used. First, composites were cooled from their melting phase temperature to ambient temperature. Second, composites were cooled from 130°C to a pre-determined and controlled temperature (T: 0°, 20°, 30°, 40°, 50°, 60°, 70°, 80°C). Third, composites were temperature-tested using annealing. The findings suggest that the elongation-at-break and impact strength may be improved following an initial quenching process from the melting phase to ambient temperature. On the other hand, a second quenching process at 0°C produces superior results, and a correlation between mechanical and thermal characteristics is noted; however, while these qualities are increased, others, such as flexibility, density, Vicat softening temperature (VST), and heat distortion temperature (HDT) are negatively impacted. [ABSTRACT FROM AUTHOR]

Mining waste represents a global issue due to its potential of generating acidic or alkaline leachate with high concentrations of metals and metalloids (metal(loid)s). Microbial-induced calcium carbonate precipitation (MICP) is an engineering tool used for remediation. MICP, induced via biological activity, aims to precipitate calcium carbonate (CaCO3) or co-precipitate other metal carbonates (MCO3). MICP is a bio-geochemical remediation method that aims to immobilize or remove metal(loid)s via enzyme, redox, or photosynthetic metabolic pathways. Contaminants are removed directly through immobilization as mineral precipitates (CaCO3 or MCO3), or indirectly (via sorption, complexes, or inclusion into the crystal structure). Further, CaCO3 precipitates deposited on the surface or within the pore spaces of a solid matrix create a clogging effect to reduce contaminant leachate. Experimental research on MICP has shown its promise as a bioremediation technique for mining waste. Additional research is required to evaluate the long-term feasibility and potential by-products of MICP-treated/stabilized waste. [ABSTRACT FROM AUTHOR]

Precipitation of marine biogenic CaCO 3 minerals occurs at specialist sites, typically with elevated pH and dissolved inorganic carbon, and in the presence of biomolecules which control the nucleation, growth, and morphology of the calcium carbonate structure. Here we explore aragonite precipitation in vitro under conditions inferred to occur in tropical coral calcification media under present and future atmospheric CO 2 scenarios. We vary pH, Ω Ar and pCO 2 between experiments to explore how both HCO 3 − and CO 3 2− influence precipitation rate and we identify the effects of the three most common amino acids in coral skeletons (aspartic acid, glutamic acid and glycine) on precipitation rate and aragonite morphology. We find that fluid Ω Ar or [CO 3 2−] is the main control on precipitation rate at 25 °C, with no significant contribution from HCO 3 − or pH. All amino acids inhibit aragonite precipitation at 0.2–5 mM and the degree of inhibition is inversely correlated with Ω Ar and, in the case of aspartic acid, also inversely correlated with seawater temperature. Aspartic acid inhibits precipitation the most, of the tested amino acids (and generates changes in aragonite morphology) and glycine inhibits precipitation the least. Previous work shows that ocean acidification increases the amino acid content of coral skeletons and probably reduces calcification media Ω Ar , both of which can inhibit aragonite precipitation. This study and previous work shows aragonite precipitation rate is exponentially related to temperature from 10 to 30 °C and small anthropogenic increases in seawater temperature will likely offset the inhibition in precipitation rate predicted to occur due to increased skeletal aspartic acid and reduced calcification media Ω Ar under ocean acidification. [ABSTRACT FROM AUTHOR]

At present, the problem of environmental pollution is becoming increasingly serious. It is urgent to develop efficient catalysts to solve these problems. To obtain the functional characteristics of CaCO3 and promote its application in coatings and photo‐catalysis, ZnO/CaCO3 particles are prepared by the solution co‐precipitation method under the mediate of sodium dodecyl sulfate (SDS) through corresponding strategies. The structures and morphologies of samples are characterized by XRD, FT‐IR, SEM, and TEM, respectively. Besides that, the photo‐catalytic property of the desired product is also evaluated. The results indicate that SDS helps to induce the formation of porous structure. Through co‐precipitation, ZnO particles uniformly load on porous calcium carbonate. ZnO/CaCO3 particles are endowed with low‐cost property and high catalytic performance under the synergistic effect of photo‐catalytic properties and absorption abilities. This work established a simple way to produce the composite catalysts with low price and high photo‐catalytic activity. [ABSTRACT FROM AUTHOR]

Wood-based functional materials have developed rapidly. But the flammability significantly limits its further application. To improve the flame retardancy, the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold, and then alternately immersed in CaCl2 ethanol solution and NaHCO3 aqueous solution under vacuum. The high porosity and wettability resulting from delignification benefited the following mineralization process, changing the thermal properties of balsa wood significantly. The organic-inorganic wood composite showed abundant CaCO3 spherical particles under scanning electron microscopy. The peak of the heat release rate of delignified balsa-CaCO3 was reduced by 33% compared to the native balsa, according to the cone calorimetric characterization. The flame test demonstrated that the mineralized wood was flame retardant and selfextinguish. Additionally, the mineralized wood also displayed lower thermal conductivity. This study developed a feasible way to fabricate a lightweight, fire-retardant, self-extinguishing, and heat-insulating wood composite, providing a promising route for the valuable application of cellulosic biomass. [ABSTRACT FROM AUTHOR]

The thermophysical properties of various types of nanofluids are often studied to find more effective working fluids for heat transfer applications. In this paper, the mass density, isobaric heat capacity, thermal conductivity, dynamic viscosity surface tension, and electrical properties of calcium carbonate-ethylene glycol (CaCO 3 -EG) nanofluids were investigated. The samples with mass fractions of 0.01, 0.02, and 0.03 were prepared with a two-step method and studied as well as pure base fluid (ethylene glycol). The measurements were conducted at temperatures between 283.15 and 313.15 K and the obtained results show the impact of CaCO 3  nanoparticles on the thermophysical and electrical properties of ethylene glycol. [ABSTRACT FROM AUTHOR]

At present, the problem of environmental pollution is becoming increasingly serious. It is urgent to develop efficient catalysts to solve these problems. To obtain the functional characteristics of CaCO3 and promote its application in coatings and photo‐catalysis, ZnO/CaCO3 particles are prepared by the solution co‐precipitation method under the mediate of sodium dodecyl sulfate (SDS) through corresponding strategies. The structures and morphologies of samples are characterized by XRD, FT‐IR, SEM, and TEM, respectively. Besides that, the photo‐catalytic property of the desired product is also evaluated. The results indicate that SDS helps to induce the formation of porous structure. Through co‐precipitation, ZnO particles uniformly load on porous calcium carbonate. ZnO/CaCO3 particles are endowed with low‐cost property and high catalytic performance under the synergistic effect of photo‐catalytic properties and absorption abilities. This work established a simple way to produce the composite catalysts with low price and high photo‐catalytic activity. [ABSTRACT FROM AUTHOR]

Carbon dioxide, as a great part of greenhouse gases, stands as a major contributor to climate change; hence, various techniques have been presented for controlling and decreasing CO2 emissions. The studies show that the adsorption and conversion into environmentally benign substances are the most practical and efficient strategies for this purpose. As amines are active in CO2 adsorption, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was chosen as an amine group to functionalize MCM-41 mesoporous in order to hydrate CO2 and convert to calcium carbonate in this study. The synthesis of the mesoporous materials and amine functionalization were carried out using the wet impregnation method, and the materials were characterized by XRD, FT-IR, SEM, and BET analysis. The results demonstrated a high adsorption capacity (165 mg CaCO3) due to the presence of the -NH2 group in the catalysts. Moreover, the results have been compared with similar mesoporous materials functionalized with metals for CO2 capture and hydration. The adsorption-desorption isotherm corresponded to type IV, as defined in the IUPAC classification. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine by SEM-EDS analysis of the surface morphologies of the periostracum and nacreous layer and to determine the sodium (Na), Strontium (Sr), manganese (Mn), potassium (K), titanium (Ti), iron (Fe), magnesium (Mg), cobalt (Co), copper (Cu), chromium (Cr), zinc (Zn) and nickel (Ni) metals levels in the shells of the mussel (Potomida semirugata, Unio terminalis, Anodonta pseudodopsis and Leguminaia wheatleyi) obtained from Gölbaşı Lake, Turkey. The results of the study, the representative SEM analysis and corresponding EDS spectra of the periostracum and nacreous layer of the shells of freshwater mussels confirmed the presence of elemental compositions, including CaCO3. P. semirugata and U. terminalis have the aragonite prismatic layer that shows typical polygonal organizing, regular and polygonal crystal forms, with hexagonal and coexisting rhombic shapes. However, while A. pseudodopsis has round aragonite crystals (Rc), L. wheatleyi has irregular crystal plate layers (Irc). CaCO3, detected strong Ca peaks as well as C and O peaks with Mg and Si peaks. On the other hand, sodium (Na) was found in the highest concentrations ranging from 82.30±0.040 to 155.37±0.050 µg/g, and its concentrations were also higher than those of other metals in all species. The most abundant elements in shells of four freshwater mussel's species were Sr, Na, and Mn which ranged from 26.07±0.44-58.023±0.52 µg/g, 82.30±0.040-155.37±0.050 µg/g, and 6.06±0.044-9.66±0.053 µg/g respectively. To our knowledge, this is the first study in Turkey that is researched the different four freshwater mussel species in the Gölbaşı Lake, Turkey. [ABSTRACT FROM AUTHOR]

Abstract Deploying energy storage and carbon capture at scale is hindered by the substantial endothermic penalty of decomposing CaCO3 to CaO and CO2, and the rapid loss of CO2 absorption capacity by CaO sorbent particles due to sintering at the high requisite decomposition temperatures. The decomposition reaction mechanism underlying sorbent deactivation remains unclear at the atomic level and nanoscale due to past reliance on postmortem characterization methods with insufficient spatial and temporal resolution. Thus, elucidating the important CaCO3 decomposition reaction pathway requires direct observation by time‐resolved (sub‐)nanoscale methods. Here, chemical and structural dynamics during the decomposition of CaCO3 nanoparticles to nanoporous CaO particles comprising high‐surface‐area CaO nanocrystallites are examined. Comparing in situ transmission electron microscopy (TEM) and synchrotron X‐ray diffraction experiments gives key insights into the dynamics of nanoparticle calcination, involving anisotropic CaCO3 thermal distortion before conversion to thermally dilated energetically stable CaO crystallites. Time‐resolved TEM uncovered a novel CaO formation mechanism involving heterogeneous nucleation at extended CaCO3 defects followed by sweeping reaction front motion across the initial CaCO3 particle. These observations clarify longstanding, yet incomplete, reaction mechanisms and kinetic models lacking accurate information about (sub‐)nanoscale dynamics, while also demonstrating calcination of CaCO3 without sintering through rapid heating and precise temperature control.

We investigated the impact of CaCO3 addition on the density and compressive strength of calcium aluminate cement (CAC)-based cementitious materials in binder jetting additive manufacturing (BJAM). To confirm the formation of a uniform powder bed, we examined the powder flowability and powder bed density for CaCO3 contents ranging from 0 to 20 wt.%. Specifically, powders with avalanche angles between 40.1–45.6° formed a uniform powder bed density with a standard deviation within 1%. Thus, a 3D printing specimen (green body) fabricated via BJAM exhibited dimensional accuracy of less than 1% across the entire plane. Additionally, we measured the hydration characteristics of CAC and the changes in compressive strength over 30 days with the addition of CaCO3. The results indicate that the addition of CaCO3 to CAC-based cementitious materials forms multimodal powders that enhance the density of both the powder bed and the green body. Furthermore, CaCO3 promotes the formation of highly crystalline monocarbonate (C4AcH11) and stable hydrate (C3AH6), effectively inhibiting the conversion of CAC and showing compressive strengths of up to 5.2 MPa. These findings suggest a strong potential for expanding the use of BJAM across various applications, including complex casting molds, cores, catalyst supports, and functional architectural interiors.

[Display omitted] Hypothesis: Hydrophobized fumed silica particles were previously reported for producing antibubbles that are quite stable in neutral as well as in acidic media. To produce acid-responsive antibubbles (e.g., for gastric drug delivery), the silica nanoparticles must be replaced by suitable particles, e.g., calcium carbonate (CaCO 3), which can degrade at low pH to release the encapsulated drug. Experiments: Two variants of CaCO 3 -stabilized antibubbles were prepared (by using CaCO 3 particles pre-coated with stearic acid, or by using native CaCO 3 particles in combination with sodium stearoyl lactylate) and drug release was compared with classic antibubbles produced with hydrophobized fumed silica particles. Findings: CaCO 3 particles (pre-coated with stearic acid) can be used to produce stable antibubbles, which provided an entrapment efficiency of a model drug (methylene blue, MB) of around 85%. A burst release of MB (∼60%) from the antibubbles was observed at pH 2 (i.e., the pH of the stomach), which was further increased to 80% during the next 30 min. On the contrary, at neutral pH, about 70% of the drug remained encapsulated for at least 2 h. We further demonstrated that the acidic conditions led to the desorption of CaCO 3 particles from the air–liquid interface resulting in the destabilization of the antibubbles and the release of drug-containing cores. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the use of nucleating agent to improve the overall performance of polybutylene adipate-co-terephthalate (PBAT) and calcium carbonate (CaCO3) composites. Specifically, sodium linoleate (Na-LL) is used as a chemical nucleating agent to improve the crystallization behavior of the material during melting extrusion processing. Mechanical, thermal, and morphological characteristics of PBAT and its composites were investigated. And a preliminary exploration was conducted on the mechanism of Na-LL improving the performance of PBAT. In this work, a formula has been obtained that dramatically saves production costs while improving product performance. After adding Na-LL to the composites, the thermal properties of the material were significantly improved, with a maximum crystallization temperature increase of 27.79 °C. In addition, composites offer superior mechanical properties compared to pure PBAT. When 0.2 parts by mass(pbw) Na-LL was added, the flexural modulus of the composites increased from 80.0 to 145.3 MPa, increased by 81.25%. The tensile performance can still be maintained at 11.0 Mpa, with elongation at break and impact strength reduced to 347.3% and 172.1 J/m, respectively. Under these conditions, it has excellent comprehensive mechanical properties. The results in this study suggest that Na-LL is a promising nucleating agent for enhancing the performance of composites and provides potential development of advanced materials for a wide range of applications in plastic packaging and plastic bags. [ABSTRACT FROM AUTHOR]

In the field of construction materials, the development of fundamental technologies to reduce energy consumption and CO2 emissions, such as manufacturing process improvement and the expanded use of alternative materials, is required. Technologies for effectively reducing energy consumption and improving CO2 absorption and reduction that can meet domestic greenhouse gas reduction targets are also required. In this study, calcium–aluminate–ferrite (CAF), a ternary system of CaO·Al2O3·Fe2O3, was sintered at a low temperature (1100 °C) to examine the possibility of CO2 adsorption, and excellent CO2 absorption performance was confirmed, as the calcite content was found to be 11.01% after 3 h of the reaction between synthetic CAF (SCAF) and CO2. In addition, the physical and carbonation characteristics were investigated with respect to the SCAF substitution rate for cement (10%, 30%, 50%, 70%, and 100%). It was found that SCAF 10% developed a compressive strength similar to that of ordinary Portland cement (OPC 100%), but the compressive strength tended to decrease as the SCAF substitution rate increased. An increase in the SCAF substitution rate led to the rapid penetration of CO2, and carbonation was observed in all the specimens after 7 days. As carbonation time increased, the CO2 diffusion coefficient tended to decrease. This is because the diffusion of CO2 in the cement matrix follows the semi-infinite model of Fick's second law. SCAF can contribute to reduced energy consumption and CO2 emissions because of the low-temperature sintering and can absorb and fix CO2 when a certain amount is substituted. [ABSTRACT FROM AUTHOR]

The challenge of continuous CaCO3 particle synthesis is addressed using microfluidic technology. A custom microfluidic chip was used to synthesize CaCO3 nanoparticles in vaterite form. Our focus revolved around exploring one-phase and two-phase synthesis methods tailored for the crystallization of these nanoparticles. The combination of scanning electron microscopy, X-ray diffraction, dynamic light scattering, and small-angle scattering allowed for an evaluation of the synthesis efficiency, including the particle size distribution, morphology, and polymorph composition. The results demonstrated the superior performance of the two-phase system when precipitation occurred inside emulsion microreactors, providing improved size control compared with the one-phase approach. We also discussed insights into particle size changes during the transition from one-phase to two-phase synthesis. The ability to obtain CaCO3 nanoparticles in the desired polymorph form (∼50 nm in size, 86–99% vaterite phase) with the possibility of scaling up the synthesis will open up opportunities for various industrial applications of the developed two-phase microfluidic method. [ABSTRACT FROM AUTHOR]

This work studied the effects of CaCO 3 additive on the phase, physical, mechanical, and microstructural properties of zirconia-toughened alumina–CeO 2 –Nb 2 O 5 ceramics prepared via wet milling. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilised to analyse the role of secondary phases, particularly hibonite, and their impact on the phase, physical, mechanical, and microstructural properties of this type of ceramic. EDX analysis showed that the hibonite phase contributed to elongated grains among the secondary phases. Vickers indentations indicated a significant difference in the compositional adjustment efficiency among the composites. Excellent Vickers hardness and fracture toughness for 1.0 wt% CaCO 3 added resulted in 7.9% hibonite at 1,422.46 HV and 5.84 MPa√m, respectively. [ABSTRACT FROM AUTHOR]

• Bacteria isolated from artefacts of different nature and conditions of conservation can exhibit great carbonatogenic abilities. • Single bacterial culture induces the precipitation of vaterite. • Bacterial community induces the precipitation of calcite. • The metastable polymorph vaterite produced by bacteria is stable during the time. Biomineralization of calcium carbonate by living organisms, including bacteria, has been studied for its potential use in conservation and restoration applications in Cultural Heritage. This study reports the carbonatogenic properties of three bacterial strains (Lysinibacillus fusiformis 3.20, Psychrobacillus psychrodurans 7Mo and Lederbergia lenta Vetro1) isolated from Il Giovane di Mozia sculpture (Mozia), the Etruscan mural paintings of the Tomba degli Scudi (Tarquinia), and a microbial community isolated from the Sant'Eustachio statue (Matera). The crystals precipitated have been investigated through a multi-analytical approach: Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The analyses showed the formation of stable vaterite by the bacterial cultures, while the microbial community induced calcite precipitation. This approach aims to support the conservation-restoration efforts, taking into the account the requests of the conservation-restorers and the unique characteristics of each Cultural Heritage artwork. [ABSTRACT FROM AUTHOR]

Nanocomposites offer enhanced mechanical properties, increased functionalities, and improved manufacturing processes by incorporating nanoscale fillers into a matrix material. Therefore, nanocomposites outperform constituent materials in mechanical, electrical, optical, and chemical properties and help to develop advanced lightweight and intelligent materials. The authors used a novel method to develop nano-reduced graphene oxide (rGO) doped nanocomposite, which is simple, fast, chemical free, and non-hazardous. Nanocomposite is synthesised using an in-house developed portable ball mill (6–9 V DC supply, 100 rpm) by varying the weight percentage (1–5%) of rGO in CaCO3. Characterisations such as Field Emission Scanning Electron Microscopy (FESEM), X-ray Diffraction, UV–Vis Spectroscopy (UV), and Raman analysis are performed to examine the morphological, optical, and chemical bonding, respectively. FESEM confirms the homogeneous mixing of two different nanoparticles. Furthermore, UV spectroscopy shows that adding rGO increases absorbance while decreasing the optical band gap from 2.04 eV to 1.83 eV. The effect of rGO doping on CaCO3 electron excitation is significant. [ABSTRACT FROM AUTHOR]

Aluminium foams have been manufactured and discovered to have a variety of uses in automotive and structural applications. However, due to their varied characteristics, it is difficult to choose an appropriate material. In this context, the selection of material for good properties is a challenging task. This study attempted to identify materials from various combinations employing the Multiple Attribute Decision Making (MADM) technique based on their mechanical and physical properties. Complex Proportional Assessment (COPRAS) is a Multi-Criteria Decision Making (MCDM) technique employed for evaluating the ranking order of the aluminium composite foam’s formulations based on performance measures. The composite foam with 2.5 wt.% of Calcium carbonate as foaming agent demonstrated the best combination of mechanical properties. [ABSTRACT FROM AUTHOR]

The development of eel fish cultivation has quite good business opportunities and prospects. However, the main obstacle in cultivating eel fish is the high mortality in the glass eel phase, so it has a survival rate of 30-50% and slow growth, namely less than 3.1%. One effort to maximize glass eel maintenance is through optimizing alkalinity as a buffer for water quality. The alkalinity level in the maintenance medium can be regulated by adding calcium carbonate (CaCO3). This research aims to determine the effect of adding CaCO3 to the rearing media on glass eels' growth and survival rate. The study was conducted for 14 days in March 2023. The method was wholly randomized with three replications in 3 treatments (P1=0 mg L-1, P2=50 mg L-1, P3=100 mg L-1). Analysis of research data used the ANOVA test. Adding CaCO3 produced a natural effect on length growth with a value of 0.16 cm, weight growth of 0.73 mg L-1, and a survival rate of 74%. The treatment did not naturally affect the alkalinity levels in the glass eel maintenance media. The best treatment effect was found in P2 (50 mg L-1). These results show that adding CaCO3 to the glass eel-rearing media decreased but did not naturally affect alkalinity levels. [ABSTRACT FROM AUTHOR]