Calcium Carbonate Compounds Research Articles

The potential of calcium oxide nanocatalyst from chicken eggshells for biodiesel production using chicken fat waste

This research aims to synthesize biodiesel using raw materials from chicken fat waste and a catalyst from eggshells (EGS). The eggshells used as a catalyst were calcined (EGS_calcined) and uncalcined (EGS_uncalcined). The calcination process was carried out at a temperature of 900 °C with a heating rate of 5 °C/minute under static air conditions for 24 h. The X-ray Diffraction diffractogram showed that the calcination process has successfully converted the calcium carbonate compound in the eggshell into calcium oxide. The particle sizes of EGS_uncalcined and EGS_calcined catalysts were 509.2 nm and 2.9 nm, respectively. Chicken fat transesterification reaction conditions were optimized to increase biodiesel yield, including variations in EGS catalyst mass (1–3 % of chicken fat extract (oil) weight), oil and methanol mole ratio (1:5–1:30), temperature (55–75 °C), and reaction time (30–180 min). The EGS catalyst mass conditions, oil and methanol mole ratio, temperature, and reaction time that produced the highest yield (93 %) were 1.5 % (w/w oil), 1:10, 65 °C, and 120 min, respectively. Research showed that the calcined EGS_catalyst performs better than the uncalcined EGS_catalyst.

Strength and self-healing behavior of bacteria biocomposite concrete in soil exposure condition

The ever-increasing extractive load on hydrocarbon resources, and growing worldwide environmental and social concern have made it necessary to find new material composites in construction that are environment friendly. Natural fibers, they being light weight, bio-renewable, low-cost and eco-friendly is recently used in various industrial applications. Microbiologically induced calcium carbonate precipitation (MICP) by bacteria added in natural fiber is investigated as possible sustainable method for strengthening and repairing cracks in concrete. In this study coir, flax, and jute fibers are used as carriers for bacterial spores to promote strength enhancement and self-healing in concrete. Bacillus tropicus added along with aforementioned natural fibers in concrete by direct addition and immobilization to determine the compressive strength, compressive strength regain and ultrasonic pulse velocity test and crack healing characteristics in concrete. Artificial cracks are induced in Bacteria Biocomposite Concrete Specimens (BBCS) to width of 0.5–1 mm and healing efficiency is determined for soil exposure condition for a period of 56 days. Bacteria added by immobilization and direct addition rendered 79.71 % and 64.49 % of enhanced healing efficiency respectively. Microstructure studies on BBCS and crack filling material (white precipitate) reveals the presence of calcium carbonate compounds, which is due to biological action of bacteria in concrete and exposure environment.

Application of Biomineralization Technology in the Stabilization of Electric Arc Furnace Reducing Slag

The unstable substances in steel slag are the main substances that affect its stability, which limits the large-scale resource utilization of steel slag. Most of the current methods for stabilizing electric arc furnace (EAF) slag are time-consuming and cannot be completely stabilized. In view of this, this study aimed to explore the feasibility of microbial-induced calcium carbonate precipitation (MICP) technology for stabilizing EAF reducing slag, and this was to be achieved by using the reaction between carbonate ions and free calcium oxide (f-CaO) in reducing slag to form a more stable calcium carbonate to achieve the purpose of stabilization. The test results showed that, when the EAF reducing slag aggregates (ERSAs) were immersed in a Sporosarcina pasteurii bacteria solution or water, the f-CaO contained in it would react such that stabilization was achieved. The titration test results showed that the f-CaO content of the ERSAs immersed in the bacterial solution and water decreased. The expansion test results of the ERSAs that were subjected to hydration showed that the seven-day expansion of ERSAs after biomineralization could meet the Taiwan regulation requirement of an expansion rate less than 0.5%. The thermogravimetric analysis showed that both the experimental group and the control group might contain calcium carbonate compounds. The results of the X-ray diffraction analysis showed that the CaCO3 content in the ERSAs that were immersed in the bacterial solution was significantly higher than those that were immersed in water. Moreover, the compressive strength test results of concrete prepared with ERSAs showed that the compressive strength of the control group concrete began to decline after 28 days. In contrast, the experimental group concrete had a good stabilization effect, and there was no decline in compressive strength until 180 days. At 240 days, the surface cracks of the experimental group were particularly small, while the surface of the control group showed obvious cracks. These results confirmed that a mineralization reaction with S. pasteurii bacteria could be used as a stabilization technology for ERSAs.

Macrobending loss in fiber optic wrapped on rubber-spring wire structure under static load-pressure

This work observes rubber-based frame structures for wide helix-shaped-macrobending fiber optic sensors intended for measuring an object with high load levels. In this fiber sensor, the working principle is to measure the power loss (due to bending) of the light traveled in the employed fiber optic. During the applications, it needs a particular mechanical structure to accommodate a reversible fiber bending in the context of load measurement. In this work, a cylindrical-shaped rubber structure mixed with calcium carbonate compound (CaCO3) is constructed as the fiber bending frame (housing) in which a spring wire is inserted into the structure in the two models, i.e., outer and inner-spring structure. Several investigations of static load pressure reveal the optimum structure design for high load measurement. Using the inner-spring model, a rubber structure with 10wt% CaCO3 exhibits the preferable performance with a sensitivity of 0.15 V/Kg.cm2 and measurement load range until 210 Kg.

Structure of an amorphous calcium carbonate phase involved in the formation of Pinctada margaritifera shells.

Some mollusc shells are formed from an amorphous calcium carbonate (ACC) compound, which further transforms into a crystalline material. The transformation mechanism is not fully understood but is however crucial to develop bioinspired synthetic biomineralization strategies or accurate marine biomineral proxies for geoscience. The difficulty arises from the simultaneous presence of crystalline and amorphous compounds in the shell, which complicates the selective experimental characterization of the amorphous fraction. Here, we use nanobeam X-ray total scattering together with an approach to separate crystalline and amorphous scattering contributions to obtain the spatially resolved atomic pair distribution function (PDF). We resolve three distinct amorphous calcium carbonate compounds, present in the shell of Pinctada margaritifera and attributed to: interprismatic periostracum, young mineralizing units, and mature mineralizing units. From this, we extract accurate bond parameters by reverse Monte Carlo (RMC) modeling of the PDF. This shows that the three amorphous compounds differ mostly in their Ca-O nearest-neighbor atom pair distance. Further characterization with conventional spectroscopic techniques unveils the presence of Mg in the shell and shows Mg-calcite in the final, crystallized shell. In line with recent literature, we propose that the amorphous-to-crystal transition is mediated by the presence of Mg. The transition occurs through the decomposition of the initial Mg-rich precursor into a second Mg-poor ACC compound before forming a crystal.

Effect of the nickel coated precipitated calcium carbonate addition on microstructure, phase and wettability of Sn-9Zn solder

This paper presents the effect of nickel-coated precipitated calcium carbonate (Ni-coated PCC) on the wettability, microstructure and phase change of Sn-9Zn solder. The microstructure and phase analysis of the material plays a very important role as it determines the physical and mechanical behavior of materials. Both Sn-9Zn and Ni-coated PCC/Sn-9Zn produced almost similar microstructure, which contain needle-like, dark phase Zn-rich phase and distributed evenly in beta-Sn rich matrix. However, compared to pure Sn-9Zn, the addition of Ni-coated PCC produce finer size of Zn rich phase needle-like structure. The presence of new phases of nickel tin and calcium carbonate compounds was also found with the addition of Ni-coated PCC. This believed to help in refining the size of Zn-rich needle structure, while retaining the original phases of Sn and Zn of the Sn-9Zn solder, Furthermore, Ni-coated PCC/Sn-9Zn have a smaller contact angle compared to pure Sn-9Zn. This can be explained that, Ni-coated PCC reinforced particle was the interfacial active element and decrease the interfacial energy between the solid and liquid. The microstructure and phase analysis of the material plays a very important role as it determines the wettability behavior of the material

Investigation of temperature sensitivity and storage stability of polyethylene and calcium carbonate compound modified bituminous binders

Investigation of temperature sensitivity and storage stability of polyethylene and calcium carbonate compound modified bituminous binders

Effect of VAE emulsion and inorganic fillers on the properties of styrene-acrylic emulsion based cement composite joint sealant

A VAE emulsion was used to replace part of styrene-acrylic emulsion, and different inorganic fillers were used alone or compounded to prepare styrene-acrylic emulsion based cement composite joint sealant (SCJS). Leveling test, pour consistency test, constant elongation test, tensile test and shear test were conducted for the SCJS. The effect of VAE emulsion dosage and different inorganic fillers on the properties of SCJS were studied through measuring the working capabilities (leveling property and pour consistency), cohesive properties (form at the fixed tensile displacement and elastic recovery rate), tensile properties (tensile strength property, tensile deformation property, tensile energy consumption performance, and tensile failure mode) and shear properties (shear strength property, shear deformation property, shear energy consumption performance, and shear failure mode) of the SCJS. The effect of VAE emulsion and inorganic fillers on SCJS pore structure was also analyzed by a MIP test. The results showed that VAE emulsion and inorganic fillers did not affect working capabilities of SCJS. With the content of VAE emulsion increased, both tensile strength and shear strength of SCJS decreased, while in general, the deformation and energy consumption indexes increased significantly, with good cohesive properties, and both tensile and shear failure modes were of cohesiveness failure. The pore volume, pore size and large pore ratio decreased significantly. When talcum powder and heavy calciumcarbonate were used alone or compounded in a 1:1 ratio as inorganic fillers, SCJS had good cohesive properties and deformation flexibility, the tensile and shear failure modes were of cohesive failure. When the talcum powder and heavy calcium carbonate were compounded as inorganic fillers, the pore volume, pore size and large pores of SCJS decreased significantly. The optimal VAE emulsion dosage ranged from 30% to 40%, and for the inorganic fillers of SCJS, 50% talcum powder + 50% heavy calciumcarbonate compound was appropriate.

Pre-Crack Behaviours of Cement Paste Containing <i>Bacillus pseudofirmus</i> ATCC 700159

The compressive strength of cement paste specimens containing Bacillus pseudofirmus ATCC 700159 was investigated in order to study the self-healing ability in cement specimens. A partial replacement of bacteria suspension by 10%, 20%, 30% and 40% by weight was mixed into the cement paste before casting. At age 28 days of curing in lime water, cement paste specimens were pre-cracked by 40% of maximum compressive strength in order to make the crack allowing moisture and air to pass through. After that, these specimens were left curing in the air until 60 days prior to the compressive test. Results showed that the specimens containing bacteria had a potential to form a new compound which was created by bacteria. XRD and FTIR analysis proved that bacteria could produce carbonate ion and therefore, combined with calcium ion in cement paste becoming calcium carbonate compound. This leads to the increase in compressive strength of pre-cracked specimens where the one with 40% bacteria giving satisfactory results of self-healing cement.

Absorption Characteristics of Novel Compound Calcium Carbonate Granules: Effects of Gastric Acid Deficiency and Exogenous Weak Acids.

Calcium carbonates are commonly administered as supplements for conditions of calcium deficiency. We report here pharmacokinetic characteristics of a novel formulation, calcium carbonate compound granules (CCCGs), forming complexes of calcium carbonate and calcium citrate in water. CCCGs were compared to a kind of commonly-used calcium carbonate D3 preparation (CC) in the market in 5-week-old mice that had been treated with omeprazole, to suppress gastric acid secretion, and in untreated control mice. The results showed that: (1) CCCGs had better water solubility than CC in vitro; (2) In control mice, calcium absorption rates after CCCGs administration were comparable to those after CC administration; (3) Inhibition of gastric acid secretion did not affect calcium absorption after CCCGs, but moderately decreased it after CC; (4) The presence of phytic acid or tannin did not affect calcium absorption rates after CCCGs but did for CC; and (5) In normal mice, CCCGs did not inhibit gastric emptying and intestinal propulsion, and did not alter the gastrointestinal hormones. The results suggest that CCCGs may be therapeutically advantageous over more commonly used calcium supplement formulations, particularly for adolescents, because of their stable calcium absorption characteristics and their relatively favorable adverse effect profile.

Control of polymorphism of calcium carbonate compounds in the cementitious materials by pH control

Control of polymorphism of calcium carbonate compounds in the cementitious materials by pH control

Pharmacutico Analytical Study of Mukta Shukti Bhasma

Background: Mukta Shukti is an aquamarine calcium carbonate compound. Mukta Shukti Bhasma is a classical ethical economical medicament, effective in general practice, pharmaceutical processing as per texts with systematic observation and technological updating is carried out in the present work. Objectives: To prepare Mukta Shukti Bhasma by different Pharmaceutical processes and carry out the analytical study. Materials and Methods: Grahya Ashodhita Mukta Shukti was subjected to Shodhana by Kanji Swedana for 3 hours and then divided into two parts. The first part of Shodhita Mukata Shukti was incinerated totally and after 1st Puta it was divided into two portions, first portion was subjected to Jala Bhavana and incinerated. The second portion was subjected to Kumari Swarasa Bhavana and incinerated. The second part of Shodhita Mukata Shukti was incinerated in Kumari Samputa and subjected to Kumari Swarasa Bhavana and incinerated until they attain Bhasma Siddhi Lakshanas and later all the three samples were subjected to analytical studies. Results: Mukta Shukti Bhasma by Jala Bhavana method, Kumari Bhavana method, and Kumari Samputa method requires 7, 6 and 3 Gajaputas respectively with an average of 324 cow dungs in each and at 793°C temperature. Conclusion: Kumari Bhavita Marana to Mukta Shukti leads to calcite form and Jala Bhavita Marana leads to calcium oxide hydrate form. Chemically Mukta Shukti Bhasma may be in both calcite and calcium oxide hydrate form, and XRD is a method in Standardization of Mukta Shukti Bhasma.

Technology of the Gramophone Records of the Music Museum by Fourier Transform Infrared Spectrometry (FTIR) Method

Music is one of the branches of the art whose helpful role and usefulness in the human’s mind and soul is undeniable. It is the only art which in the philosophers’ divisions is directly linked with the human spirit and immediate overflows the ears of his soul. The sound, as a psychological phenomenon is associated with the emotion and excitement so that sometimes calms and sometimes confuses the human. This study aims to examine the technology of the gramophone records in the Music Museum by Fourier transform infrared spectrometry (FTIR). The method of this research is experimental and the data are collected by documentation, library, and using FTIR tests. Some records of the Music Museum were studied including four samples of 78 rpm platter (stone platter), one sample of 45 rpm, and one sample of 33 rpm (vinyl platter). The results of the FTIR test indicated that the materials of the records were vinyl and shellac and in their raw material, some of the softening additives (phthalates) and fillers (silica and calcium carbonate compounds) had been used.

Characterization of crystalline structures in Opuntia ficus-indica.

This research studies the crystalline compounds present in nopal (Opuntia ficus-indica) cladodes. The identification of the crystalline structures was performed using X-ray diffraction, scanning electron microscopy, mass spectrometry, and Fourier transform infrared spectroscopy. The crystalline structures identified were calcium carbonate (calcite) [CaCO3], calcium-magnesium bicarbonate [CaMg(CO3)2], magnesium oxide [MgO], calcium oxalate monohydrate [Ca(C2O4)•(H2O)], potassium peroxydiphosphate [K4P2O8] and potassium chloride [KCl]. The SEM images indicate that calcite crystals grow to dipyramidal, octahedral-like, prismatic, and flower-like structures; meanwhile, calcium-magnesium bicarbonate structures show rhombohedral exfoliation and calcium oxalate monohydrate is present in a drusenoid morphology. These calcium carbonate compounds have a great importance for humans because their bioavailability. This is the first report about the identification and structural analysis of calcium carbonate and calcium-magnesium bicarbonate in nopal cladodes, as well as the presence of magnesium oxide, potassium peroxydiphosphate and potassium chloride in these plants. The significance of the study of the inorganic components of these cactus plants is related with the increasing interest in the potential use of Opuntia as a raw material of products for the food, pharmaceutical, and cosmetic industries.

Tribological and Antioxidation Synergistic Effect Study of Sulfonate-Modified Nano Calcium Carbonate

A middle base number sulphonate-modified nano calcium carbonate (SMC) with an average size of 35 nm was synthesized, and its tribological and antioxidation synergistic behaviors with ashless antioxidant N-phenyl-α-naphthylamine (T531) in hydrogenated oil (5Cst) were evaluated. The results demonstrate that adding this synethesized additive even at a low amount (<2.0 wt.%) can evidently improve its load-carrying capacity by 1.5 times and enhance its antiwear performance; in addition, the friction-reducing effect of additive in the high load was better than that in low load. The SMC have a good synergistic antioxidation effect with T531, which verifies the nano calcium carbonate compound was a kind of multifunctional and high-performance additive. The chemical composition of the rubbing surface which formed on the boundary film was analyzed by using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicating that the excellent antiwear and load-carrying performance could be attributed to the forming of boundary lubrication film which composed of calcium carbonate, oxides, ferrites, sulphide and FeSO4, and so on. Its ability to increase oxidation free energy of base oil is the main reason for increasing its antioxidant collaboration property with ashless antioxidant T531.

Fume Suppression Agents For Environmental-Friendly Asphalt Pavement

Abstract According to the impact of fumes generated by asphalt pavement construction under poor air ventilation conditions on environrnent and operators at pavement construction and mechanism of asphalt fumes generation this article provides the method of addition of addictives in asphalt to suppress fumes due to asphalt pavement construction. Through in house test the variation law of asphalt fames with heating temperature and heating time. The result shows that with an increase of heating time, the yield of asphalt fumes appears increasing tendency. During the initial stage, the smoke yielding rate is fast; in later stage the vaziation slows down; and finally the variation becomes stable. With higher heating temperature, the yield of asphalt fumes is greater. Paztial addictives aze selected for smoke suppression effect test from flame retardant agent, plastic smoke suppression agent, physical adsorbent, polymer modified agent and aging resistant agent. SBS and manometer calcium carbonate compound type m...

Spectroscopic characterisation of moonmilk deposits in Pozalagua tourist Cave (Karrantza, Basque Country, North of Spain)

Composition of moonmilk deposits located in different zones of the tourist Dolomite Cave of Pozalagua (Karrantza, Basque Country, North of Spain) was established by Raman spectroscopy. The deposits were located in column bases and detached rocks near a gour full of water or a dripping zone. Hydromagnesite (Mg 5(CO 3) 4(OH) 2·4H 2O) with a strong Raman band at 1116 cm −1 and weaker ones at 1522vw, 1487vw, 1452vw, 756w, 727w, 466w, 434w, 371w, 327m, 291w, 258w, 247vw and 230 m cm −1 was found as the main component of the moonmilk. Aragonite is the unique calcium carbonate compound that sometimes composes the moonmilk but always together with the hydromagnesite. Among non-carbonate minerals, some nitrates (nitrocalcite, niter, nitromagnesite, nitratine and gwihabaite) and sulphates (arkanite) were also identified as minor compounds. Most of the deposits were matt white and pasty, but occasionally some samples appear greyish on the surface. In these samples, carbon particles were also found, apart from the above, and Raman shift changes were observed in the hydromagnesite spectra. Apart from the elements involved in the mentioned minerals, Si, Fe, Mn, Zn and Ti were identified by X-ray microfluorescence as trace elements and the results were correlated with mineral compositions found by Raman measurements. Furthermore, quantification of the soluble salts of moonmilk deposits was carried out by ionic chromatography and the results were chemometrically treated to find correlations among soluble ions and the composition of the mineral phases spectroscopically characterised.

XRD, SEM/EDX and FTIR Characterization of Brazilian Natural Coral

In the present work, natural coral from Brazilian reefs were studied according to their crystallography by X-ray diffraction and microstructure by Scanning Electron Microscopy (SEM/EDX). FTIR spectroscopy was also used to evaluate the chemical functionalities and major components present in the material. The SEM morphology results have shown a tri-dimensional coral structure with porous ranging from 50 to 200 µm. Aragonite was identified as the major crystalline phase through XRD analysis and FTIR spectroscopy. Strontium calcium carbonate, (Sr,Ca)CO3, was also identified by XRD analysis. After sintering at 900º/1h, the conversion from aragonite to CaO and calcite was observed. These results have endorsed the high potential application of natural coral materials as 3D scaffolds for biomedical application, because of calcium carbonate compounds can be converted to HA by hydrothermal and biomimetic coating processes.

New dispersion process for submicronic fillers in thermoplastics

The addition of sufficiently small-sized fillers in thermoplastics is supposed to allow an increase in stiffness while maintaining a good resilience. However, it is often difficult to obtain a good impact resistance because the dispersion of fine fillers is not perfect - even using a powerful tool like a corotating twin screw extruder. This implies that the material will inevitably contain agglomerates that will cause a drastic drop in the material's resistance, bringing it down to the level of that of a coarse-filler containing material. CERDATO, jointly with APPRYL, has designed a patented process for the dispersion of fine fillers in an extruder that allows this problem to be solved. The originality of this process lies in the optimization of the deagglomeration of the filler before its feeding into the extruder. As an example, polypropylene/submicronic calcium carbonate compounds show a joint gain in stiffness and impact resistance, while a traditional incorporation process (fillers fed in the melt) leads to an important loss in impact resistance.

Ultrastructure and Electron Spectroscopic Diffraction Analysis of the Sternal Calcium Deposits of Porcellio scaber Latr. (Isopoda, Crustacea)

Calcium deposits of the first four anterior sternal plates of the terrestrial isopod Porcellio scaber must be quickly mobilized after ecdysis of the posterior half of the cuticula. The structural configuration of these deposits was examined by scanning electron microscopy, energy filtered transmission electron microscopy, and energy spectroscopic electron diffraction analysis. The deposits consist of an opaque region built by spherules of diameters varying from 0.3 to 1.7 μm and a translucent layer glassy in appearance. Both parts are composed of an organic matrix and an amorphous calcium carbonate compound. The deposition of calcium carbonate in numerous small spherules and in an amorphous form probably facilitates its quick mobilization.