Calcium Compounds Research Articles

Phase formation and carbonation impact on the strength of alkali-activated demolition waste with calcium compounds

The present study evaluates the impact of calcium compounds on the reaction kinetics of alkali-activated construction demolition waste. Two materials, concrete and brick demolition waste, were milled to powders and supplemented with either carbonated cement stone or freshly ground cement stone. The mixed solids were further subjected to alkaline activation using a sodium silicate solution. X-ray diffraction, isothermal conduction calorimetry, thermogravimetric analysis, scanning electron microscopy and compressive strength tests were employed to understand the interaction of the reactants. The results indicate that cubes prepared from freshly ground cement stone exhibited higher compressive strength of around 18 MPa than those from carbonated cement stone with a maximum of 7 MPa. This superior strength was approved by subsequent analysis methods. A more significant reaction was observed in the material containing freshly ground cement stone, resulting in increased strength within the system. The presence of portlandite in freshly ground cement stone facilitated the initial formation of calcium silicate hydrate phases.

Investigating a Calcium Alginate-Xylitol Coating Methodology for Controlled Release Profiles of Multivitamin Tablet as a Model Drug

The drug delivery system promotes the release of the active pharmaceutical ingredient (API) to attain the desired therapeutic effect at the time most needed. Alginate is a natural polymer that is frequently employed in drug delivery systems. Calcium alginate can simply coat as a film type on the surface of a tablet, which might be created to be dissolved more quickly and predictably manners in the gastric fluid to deliver as needed in a patient-friendly system. In this study, the sodium alginate solution was reacted with a predetermined calcium compound and xylitol combination, while the multivitamin tablets’ surface was coated with calcium suppliers such as calcium chloride. Then, the coated tablets were subjected to a dissolution test in a simulated gastric fluid. Our study results showed that the sphere formation was excellent in terms of strength and size in 1.0% sodium alginate with 4% calcium chloride. Average sphere sizes were 0.5 ~ 2.0 mm. Their break force was 3.5 N, And the dissolution was the fastest in the coated tablets with 1% sodium alginate and calcium chloride. The dissolution rate was changed proportionally with calcium concentration. A high feasibility of dissolution rate was positively found. When a high concentration of xylitol was mixed with 4% calcium chloride, the dissolution rate was proportional to the concentration of xylitol. In conclusion, the study demonstrated that the dissolution rate of tablets with API might be controllable with the calcium alginate film coating with xylitol.

Structural Analyses of Polysaccharides Extracted from Cyanobacterial Extracellular Gels and Oriented Liquid Crystalline Microfiber Processing by Poly(vinyl alcohol)-Assisted Electrospinning.

Sacran is a supergiant cyanobacterial polysaccharide that forms mesogenic supercoil rods that exhibit liquid crystalline (LC) gels at deficient concentrations of around 0.5 wt%, and has several bioactive stimuli-responsive functions. Here, we attempted to form oriented microfibers of sacran by electrospinning, following structural analyses of the sacran rods. A heterogeneous acid-hydrolysis method using a protonated cation-exchange resin was adopted to examine the short-time exposition of concentrated acid to sacran rods. From the supernatant, the oligomeric fraction that was soluble in water and methanol was isolated. The oligomeric fraction had a main sugar ratio of α-Glc:β-Glc:α-Xyl:β-Xyl:α-Rha of 2:5:1.5:1.5:4 (Glc:Xyl:Rha = 7 (=4 + 3):3:4), and it was speculated that the sacran structure includes rhamnoglucan and xyloglucan (4:3), which are generally rigid enough to exhibit LC. To make oriented microfibers of LC sacran, solubility testing was performed on sacran to find good new solvents of polyhydroxy alcohols such as ethylene glycol, 1,2-propanediol, and glycerol. The oriented film was prepared from a sacran aqueous solution where calcium compound particles deposited on the film are different from polyhydroxy alcohol solutions. Although sacran could not form microfibers by itself, polymer composite microfibers of sacran with poly(vinyl alcohol) were prepared by electrospinning. Cross-polarizing microscopy revealed the molecular orientation of the microfibers.

Potential use of a bone tissue engineering scaffold based on electrospun poly (ɛ-caprolactone) - Poly (vinyl alcohol) hybrid nanofibers containing modified cockle shell nanopowder

Today, the construction of scaffolds promoting the differentiation of stem cells is an intelligent innovation that accelerates the differentiation toward the target tissue. The use of calcium and phosphate compounds is capable of elevating the precision and efficiency of the osteogenic differentiation of stem cells. In this research, osteoconductive electrospun poly (ɛ-caprolactone) (PCL) - poly (vinyl alcohol) (PVA) hybrid nanofibrous scaffolds containing modified cockle shell (CS) nanopowder were prepared and investigated. In this regard, the modified CS nanopowder was prepared by grinding and modifying with phosphoric acid, and it was then added to PVA nanofibers at different weight percentages. Based on the SEM images, the optimum content of the modified CS nanopowder was set at 7 wt %, since reaching the threshold of agglomeration restricted this incorporation. In the second step, the PVA-CS7 nanofibrous sample was hybridized with different PCL ratios. Concerning the hydrophilicity and mechanical strength, the sample named PCL50-PVA50-CS7 was ultimately selected as the optimized and suitable candidate scaffold for bone tissue application. The accelerated hydrolytic degradation of the sample was also studied by FTIR and SEM analyses, and the results confirmed that the mineral deposits of CS are available approximately 7 days for mesenchymal stem cells. Moreover, Alizarin red staining illustrated that the presence of CS in the PCL50-PVA50-CS7 hybrid nanofibrous scaffold may potentially lead to an increase in calcium deposits with high precipitates, authenticating the differentiation of stem cells towards osteogenic cells.

Characterization of Lateralite: An Environment Friendly Chemical Additive for Soil Stabilization

The objective of this paper is to determine the chemical composition of Lateralite stabilizer and to characterize Lateralite, stabilizer as a solution for improving the engineering properties of fined grained lateritic and clayey soil for road construction. Oxides and metallic compositions of Lateralite was determined by Atomic Absorption Spectroscopy, AAS, composition of chemical elements of Lateralite stabilizer was determined by X-ray Photoelectron Spectroscopy (XPS) and a quantitative analysis by Scanning Electron Microscopy (SEM) associated with Energy Dispersive X-ray spectroscopy (EDX). The oxide composition of Lateralite as determined by AAS is: Calcium Oxide (63.89%), Silicon Oxide (18.31%), Aluminium Oxide (5.89%), Ferrous oxide (1.67%), Magnesium oxide (1.56%), Sulphur oxide (1.22%), Potassium oxide (0.78%), Sodium oxide (0.41%) and L.O.I 6.27%. The elemental composition analysis by XPS revealed ten (10) elements with Percentage Atomic Concentration, PAC, as: Oxygen (54.33%), Carbon (18.26%), Silicon (9.38%), Calcium (7.56%), Magnesium (4.08%), Aluminium (2.90%), Sodium (2.47%), Ferrous (0.44%), Sulphur (0.31%) and Nitrogen (0.27%) while SEM revealed eleven (11) elements: Oxygen (57.9%), Calcium (21.13%), Silicon (11.08%), Aluminium (4.23%), Ferrous (1.89%), Sulphur (1.07%), Magnesium (1.02%), Sodium (0.99%), Potassium (0.35%), Tin (0.18%) and Barium (0.17%). The three (3) characterization techniques used, (AAS, XPS and SEM) revealed the exchangeable cations in Lateralite are Calcium (7.56%), Magnesium (4.08%), Aluminium (2.90%) and Sodium (2.47%) which are in the ratio 3: 1.65:1.17:1, (Ca2+: Mg2+: Al3+ :Na+). This shows a high concentration and quantity of exchangeable calcium cations over other cations. This will enable the formation of Calcium compounds with very strong and stable inter-particle bonds and a stable Lateralite-stabilized soil mixture.

Assessing the applicability of a special model of plutonium behavior in presence of chelates in cases of wound intake of industrial compounds of plutonium in the FSUE Mayak PA workers

In cases of intake of higher levels of plutonium, a chelate diethylenetriaminepentaacetic acid is used to enhance the elimination and reduce deposition rate in the organs of major deposit in the form of calcium compound Ca-DTPA (pentacinum). To interpret the results of the nuclide measurements in excreta while estimating the doses of internal exposure to plutonium, the biokinetic and dosimetry models recommended by ICRP are applied; and in case of the actinide intake through damaged skin it is recommended to use the models of NCRP of the USA. Since the application of chelates significantly changes the picture of plutonium urinary excretion, special models of complex Pu-DTPA behavior are developed to describe the plutonium biokinetics in presence of chelates. The purpose of this work is to assess the suitability of a special model of plutonium behavior in presence of chelates elaborated by K. Konzen to describe the plutonium biokinetics in the body by the cases of wound intake of industrial plutonium compounds in the FSUE Mayak PA workers. This study used the measurements of plutonium activity in daily amount of urine for three cases with the actinide intake through damaged skin and Ca-DTPA treatment, the duration of pentacinum application and observation periods for workers depending on the levels of intake. For each case, the most likely type of an entered compound was selected using Akaike information criterion, then the daily urinary activity of plutonium was calculated by the model (estimated value) on the same days when it was determined actually (actual values). The analysis of the compliance of calculated data with actual data was conducted using the statistic tests of Foster-Stewart,Breusch-Godfrey, Mann-Whitney, Shapiro-Wilk, and the determination coefficient. It was found that for all cases considered, the adjusted determination coefficient and Foster-Stewart test indicated the compliance of actual data with calculated ones. The statistical analysis of the compliance of calculated data with actual measurements of plutonium urinary activity showed that the special model of plutonium behavior proposed by K. Konzen was able to predict the urinary activity of plutonium during both the radionuclide decorporation measures and the period of pentacinum aftereffect.

URANIUM BEHAVIOR DURING THE FORMATION AND SUBSEQUENT STORAGE OF SOLID RADIOACTIVE WASTES FROM CONVERSION PRODUCTION

A complex of physicochemical studies of solid radioactive wastes (RW) of the near-surface storage facility from conversion uranium production was carried out. It has been established that the composition of the wastes is represented mainly by calcium compounds: gypsum, calcite, and calcium fluoride. Uranium is distributed throughout the entire volume of wastes. At the same time, uranium is unevenly concentrated along the depth of the sludge. The content of uranium in the wastes is 0.005-0.65 wt. %. Uranium was predominantly adsorbed on the surface of sludge by main components during the formation of the wastes solid phase. Uranium was partially precipitated in the form of calcium-containing weeksite Ca2(UO2)2(Si2O5)3·10H2O, uranophane-alpha Ca(UO2)2(SiO3OH)2·5H2O, and urankalcarite Ca(UO2)3CO3(OH)6·3H2O. The isotopic composition of uranium contained in the storage wastes corresponds, within the error, to the normal isotopic composition of natural uranium. Near-surface storage is constantly exposed to natural factors. Infiltration of atmospheric condensation leads to leaching of some components from solid RW. At the same time, uranium goes into solution in the form of [(UO2)2CO3(OH)3]-, [UO2(CO3)2]2-, [UO2(CO3)3]4- and Ca2UO2(CO3)3. The subsequent migration of uranium with infiltrating water contributes to its distribution within the entire sludge field, including the reclamation soil layer and the near-surface pond. In some areas of the storage facility, the uranium content in the reclamation soil layer reaches 0.043 wt.%. The concentration of uranium in the pond was 17.97 mg L-1. The chemical composition of the pond water was characterized by a high content of chloride-ions (1.29 g L-1), calcium (630 mg L-1), sulfate-ions (224 mg L-1), hydrocarbonates (122 mg L-1). The pond is connected to groundwater, which increases the risk of pollutants escaping beyond the storage facility. For citation: Skripchenko S.Yu., Titova S.М., Nalivaiko K.A., Semenishchev V.S. Uranium behavior during the formation and subsequent storage of solid radioactive wastes from conversion production. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 5. P. 77-86. DOI: 10.6060/ivkkt.20246705.6925.

Antihypoxic effect of almid-containing metal-complex compounds in the experiment

BACKGROUND: To increase resistance to hypoxia, various methods of hypoxic training, mental effects, and use of pharmacological antihypoxants are employed.
 AIM: To test new metal-complex compounds containing the antihypoxant almid in mice under conditions of acute hypoxia to determine their protective properties.
 MATERIALS AND METHODS: In the first stage of the study, four new metal-complex compounds of magnesium, calcium, titanium, and vanadium containing the antihypoxant almid were screened in experiments on mice (n = 550) under acute hypoxic conditions with hypercapnia. The antihypoxants almid and amtizole were used as comparison substances. Acute hypoxia was induced by placing the animals in pharmacy glasses with a volume of 0.25 L with closed lapped stoppers. The substances were administered intraperitoneally at doses of 25, 50, and 100 mg/kg previously dissolved in 0.3 mL of NaCl solution. The incubation period was 60 min. The antihypoxic effect was considered confirmed if the lifespan increased by ≥20%. “Lifespan” refers to the time interval from the moment the mice were placed in a pharmacy glass to the development of the first agonal inhalation, after which the animals were quickly removed to preserve life. The rectal temperature of the animals was measured before the introduction of substances, immediately before being exposed to acute hypoxic conditions with hypercapnia, and after removal. Twenty-four hours after the first stage of the experiment, mice of the control group and mice that proved their ability to resist acute hypoxia with hypercapnia were repeatedly exposed to acute hypoxic conditions with hypercapnia after the use of substances.
 RESULTS: A distinct antihypoxic effect exceeding the effectiveness of the comparison substances was obtained only in one substance—πQ2460 with titanium as a metal-complexing agent—and a ligand in the form of fumaric acid. After the administration of πQ2460, a dose-dependent decrease in rectal temperature was observed in mice. The lifespan of animals increased with an increase in the dosage of πQ2460, i.e., by 43.9%, 103.1%, and 152.8% for doses of 25, 50, and 100 mg/kg, respectively. The results of the second stage of the experiment confirmed the stable protective effect of πQ2460 but with an equalization of the effect of the studied doses, which increased the lifespan under acute hypoxic conditions with hypercapnia to an average of 60–70 min (control group, 40.5 min).
 CONCLUSION: Among the compounds containing the antihypoxant almid in the complex molecule, πQ2460 (metal, titanium; ligand, fumaric acid) was found to have a stable protective dose-dependent effect on the development of acute hypoxia with hypercapnia in mice exceeding that for almid and the reference antihypoxant amtizole. The antihypoxic effect of πQ2460 persisted 24 h after its administration but leveled off for the studied doses—25, 50, and 100 mg/kg. Considering the data obtained during the comparison of the indicators of resistance to acute hypoxia in the control group, a hypothesis was proposed regarding the possibility of forming a preconditioning effect in animals from the primary effects of acute hypoxia.

Role of Rasoushadhies in the management of alcoholic acute on chronic pancreatitis: A case study

Pancreatitis is inflammation of the pancreas, which may be acute or chronic. Acute pancreatitis is an acute inflammatory condition that may extend to local and distant extrapancreatic tissues. Recurrent inflammations will eventually turn the disease into a chronic stage. The chronicity of the disease causes emaciation of the patient, craving for food, and worsening of the symptoms, which results in a bad prognosis due to necrosis of the pancreatic cells, depicting the Dhatupakavastha (~tissue suppuration) as per Ayurveda. The predominant symptom is persistent Udarashoola (~colicky abdominal pain). The management of pancreatitis through Rasoushadhi (~herbo-metallo-mineral-based formulations) is considered to be a choice of treatment due to its advantages, including an ability to cure even bad prognostic diseases. This is a case study of a 48-year-old male, a diagnosed case of alcoholic acute on chronic pancreatitis since 2009, where administration of a combination of few Rasoushadhi containing Lauha bhasma (~incinerated iron), Tamra bhasma (~incinerated Copper), Sudhavarga dravya (~calcium compounds), and Kshara (~alkaline substances) showed significant improvement in clinical, biochemical, and radiological parameters. The outcome of the treatment infers that Rasoushadhi can be useful in the management of such manifestations, further can reduce in number of hospitalizations and restore the health of the patient.

Analysis of bioleaching characteristics and multi-element dissolution behavior of complex zinc ores

In order to recover low-grade complex zinc ore in a reasonable way, this study adopts bioleaching method to study it. The ore samples contain 1.52%, 2.03% and 14.4% zinc, respectively, which occurs in the form of sphalerite. Other major minerals include pyrite, galena, quartz and mica. The inoculation of the domesticated strain was basically free of adaptation period, and the cell concentration could be rapidly increased after a short decrease. The leaching extent of zinc increased continuously, while the leaching rate decreased gradually. After the bioleaching process, sliver, lead and iron were mainly present in the residue phase. X-ray diffraction spectroscopy analysis showed that sphalerite, galena and pyrite were dissolved, and the latter two further precipitated to produce PbSO4 and jarosite. In addition, the dissolution of calcium compounds can lead to the formation of gypsum precipitation. These precipitates covered the fresh ore surface may hinder the further bioleaching process. The Exponential model was used to simulate the bioleaching process, and it was found that the fit coefficients were all greater than 0.98, and a reasonable leaching cycle was further discussed. The results provide a good basis for the economic and environmentally friendly recovery of low-grade complex zinc ores.

Pengaruh Pemberian Ekstrak Cangkang Telur Bebek (Anas Plaptyrhynchos Domesticus) Konsentrasi 20% Dalam Sediaan Gel Dan Pasta Terhadap Kekerasan Permukaan Email Gigi Tikus Wistar (Rattus Norvegicus) : Studi (In Vivo)

Dental caries is a disease of the hard tissues of the teeth which is characterized by damage to the email and dentin caused by bacterial activity in fermented carbohydrates. One way to overcome and prevent caries is by giving anticariogenic substances that can inhibit caries development and trigger remineralization. As for other alternative materials used for remineralization, one of them is duck egg shell (Anas platyrhynchos domesticus) because it contains calcium carbonate which is in the eggshell can be converted into hydroxyapatite or calcium compounds, so that it can be used as the formation of damaged bones and teeth. In this study, duck egg shell hydroxyapatite extract was made in gel and paste preparations. In gel preparations, it has a high adhesive power so that the absorption on an email surface will be maximized. While in the preparation of pasta also has a great absorption power. This study aimed to determine the effect of hydroxyapatite gel and paste from duck eggshell extract (Anas platyrhynchos domesticus) and Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) on the tooth email hardness of wistar rats (Rattus norvegicus). In this study there were 3 treatment groups. Prior to treatment, the tooth sample was etched in the labial section for 20 seconds and rinsed using a brush and water. After etching was applied, in group 1, duck egg shell hydroxyapatite extract gel was applied, in group 2, duck egg shell hydroxyapatite extract paste was applied, and in group 3 as a control group, CPP-ACP was applied to the lower anterior teeth of wistar rats for 30 minutes 2 times a day. for 14 days. On the 15th day, the lower anterior teeth were decapitated by wistar rats and hardness testing was carried out using microvikers hardness in the labial part of the teeth. This research is a true experimental with Post Test Control Group Design. The result of the average hardness of email that has been treated with the highest hardness is CPP-ACP of 332 VHN. The results of the normality test using Shapiro Wilk showed that the duck egg shell extract gel could increase the surface hardness of tooth email. The results of the comparison test using Kruskal Wallis showed that there was a change in hardness between the hydroxyapatite gel of duck eggshell extract, hydroxyapatite paste of duck eggshell extract and CPP-ACP and there were significant differences. From the results of this study, there was an increase in the surface hardness of tooth email after the application of duck egg shell hydroxyapatite gel (Anas platyrhynchos domesticus) compared to paste preparations and as a positive control with CPP-ACP also increased the hardness of tooth email.

Understanding the solid-state calcium metavanadate synthesis pathway

The calcium metavanadate (CaV2O6) synthesis was studied by a conventional solid-state reaction in a CaCO3 - V2O5 mixture (1:1) molecular ratio in air. The synthesis began at 400 ºC and at temperatures above 620 ºC speeds up due to formation of an eutectic compound. After one hour at 650 ºC complete synthesis of the metavanadate is achieved. The crystal phase and the particle morphologies of the CaV2O6 were analyzed by Powder X-ray Diffraction (PXRD), Energy Dispersive Spectroscopy (EDS) and Scanning Electron Microscopy (SEM). A single phase and rounded particles with smooth faces were found. The combination of several experiments allowed the determination of the synthesis pathway, which occurred from CaCO3 and not from CaO. If the starting calcium compound is the oxide, the first step could be carbonation process with the atmospheric CO2.

Influence of Blending High-Calcium Additive on Environmental Safety of B, F, and Se: A Case Study from Thermodynamic Calculation

Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer systems and soil. To study the transformation of TEs, a thermodynamic calculation (FactSage 7.2) was used. Paper sludge ash was used as a calcium compound additive. The influence of blending a high-calcium additive on the environmental safety of TEs was investigated based on the effect of the mass addition ratio of PS ash. This study’s results confirmed that the leaching processes of TEs, namely (CaO)2(Al2O3), CaF2, Ca10(PO4)F2, and CaSeO4(H2O)2, were caused by the formation of B, F, and Se compounds during the leaching process. Thus, it is clear that calcium has the greatest influence on the transformation of TEs due to their reaction, which, in turn, minimizes the effects of the TEs’ release into the environment. The concentrations of TEs from the sample and addition of PS ash decreased slightly, indicating that the inhibition of TEs was enabled through the addition of PS ash. Although the PS ash YB had the highest calcium content, the PS ash YC gave the best results during the B and Se inhibition processes. The experimental observation was also evaluated for comparison. For the analysis of TEs’ leaching ratios using the thermodynamic calculation and experiment, the experimental results were lower than those initially predicted. These results will help us to choose the best available control technology to minimize the effects of TEs released into the environment.

Nutritional Profiling and Characterization of Developed Cake Premix Using Finger Millets (Eleusine coracana) and Sweet Potato (Ipomea batatas L.)

Research in the areas of nutrition and health care, as well as the growing public knowledge of these subjects, support the potential of phytochemicals like dietary fibre on their health-beneficial properties. Finger millet (FM) rates higher in terms of nutritional composition than other cereal grains. When absorbed by the body, FM's nutritional composition lowers the chance of developing type 2 diabetes, hypertension, and gastrointestinal tract disorders. Due to the high levels of calcium (0.38%), dietary fibre (18%), and phenolic compounds (0.3–3%) in it, its usefulness in terms of nutrition is well understood. Additionally, they have been found to have anti-diabetic, anti-tumor, anti-atherosclerotic, antioxidant, and antibacterial activities. The study focused on the development, Physiochemical Analysis, Nutritional Profiling and Microbial analysis of Cake Premix using Finger Millet and Sweet Potato in Different Ratio. A porous shape of the premix powder was shown by Scanning Electron Microscope-Energy Dispersive Spectroscopy. The structure of the Premix was mainly pore-free, uniform, and compact. showed that the Premix's surface was also smooth. Presumption powder's Fourier-transform infrared spectroscopy (FTIR) spectra were essentially identical within the wave-number range of 4000–400 cm−1. the six-month period's microbiological proliferation (count of mould and yeast). The findings showed that during the storage period, there was no discernible variation in the microbiological load (yeast and mould count) in the created goods, suggesting that they were safe for ingestion for up to six months. The objective of the present research was intended to develop Cake premix by using Finger Millet and Sweet Potato in different Ratio which could be utilized as nutritional supplement and also helps in lowering the risks of lifestyle disorders.

Simulation of the bone remodelling microenvironment by calcium compound-loaded hydrogel fibrous membranes for in situ bone regeneration.

The endowment of guided bone regeneration (GBR) membranes with the ability to activate the endogenous regenerative capability of bone to regenerate bone defects is of clinical significance. Herein we explored the preparation of the calcium compound (CC) (calcium sulfate (CaSL), calcium hydrophosphate (CaHP), or tricalcium phosphate (TCaP)) loaded ultrathin silk fibroin (SF)/gelatin (G) fibre membranes via electrospinning as the GBR membranes to regenerate the calvarial bone defects. The in vitro experiments demonstrated that the CaSL-loaded ultrathin fibrous membranes could simulate optimally the bone remodelling microenvironment in comparison with the CaHP- and TCaP-loaded fibrous membranes, displaying the highest activity to regulate the migration, proliferation, and differentiation of mesenchymal stem cells (MSCs). Also, the in vivo experiments demonstrated that the CaSL-loaded fibrous membranes presented the highest intrinsic osteoinduction to guide in situ regeneration of bone. Furthermore, the in vivo experiments demonstrated that the as-prepared composite fibrous membranes possessed good degradability. In summary, our results suggested that the CaSL-loaded fibrous membranes with high intrinsic osteoinduction and good degradability have potential to translate into clinical practice.

EVIDENCE OF MICROBIAL ANTAGONISM IN VOLCANIC TUFF ROCK

A total number of 64 bacterial strains isolated from two volcanic tuff rock located in Teisani, Prahova, and Malul Alb, Buzau areas were investigated for ability to producing factor with antagonistic activity (AF). From these, 59 strains have the ability to synthesis AF acting against other strains isolated from these ecosystems. Some of the strains (1-2 and 1-7 respectively, isolated from Malul Alb) are acting as antimicrobial against pathogenic strains Staphyloccocus aureus and Lysteria monocytogenes. Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray fluorescence (XRF) analysis revealed a chemically composition based on the compounds of silica, calcium, potassium, aluminum, iron and titanium as well as the presence of groups characteristic to organic compounds. A relatively high number of microbial strains as colony-forming units (CFU) were quantified at 7x104 for the Teişani sample and 1.5x105 for the Malul Alb sample per gram of rock.

A Continuous Extraction Protocol for the Characterisation of a Sustainably Produced Natural Indigo Pigment.

The sustainable industrial production of indigo necessitates a unique extraction process to separate the plant-derived compounds. Calcium compounds are added to encourage hydrolysis of these precursors and to facilitate the isolation of the final form, resulting in an organic-inorganic composite pigment with unspecified characteristics. In this study, we devised a continuous solvent extraction procedure to fractionate the organic indigoid phase within the composite pigment. Overcoming challenges posed by limited solubility in the common organic solvents, this method allows for the analysis of individual fractions, significantly enhancing resolution. Comprehensive characterisation using spectroscopic analysis, thermogravimetry, and UHPLC-MS/MS revealed the potential for quantifying primary components of the natural pigment and distinct differentiation from the synthetic dye. This approach also holds promise for establishing robust manufacturing practices in the industrial production of natural indigo.

An analysis of the interaction of infiltration waters from tungsten ore processing tailings and limestone

An experimental plant designed to study the interaction of acidic pore waters in tailings ponds was developed. The study showed that processing tailings of the Dzhida tungsten-molybdenum plant contain residual ore mineralization, which decomposed during long-term storage. The filtrate obtained by washing sand with distilled water contains sulfur, aluminum, iron, manganese, zinc, copper, cadmium and other components. To displace all dissolved substances from the pore space of sand, the threefold volume of water is sufficient. When the filtrate is neutralized with limestone under the dynamic conditions, amorphous compounds of iron, calcium, aluminum, sulfur, silicon, and fluorine are precipitated and the minerals gypsum, dolomite, and smithsonite appear. In addition, precipitation of non-ferrous and rare earth elements occurs on the surface of limestone. The study revealed an europium anomaly. To precipitate rare earth elements from a solution, it is necessary to use substances with an active surface.

Bio-sourced Hydroxyapatite is better bioactive than its synthetic grade: A comparative assessment of Ti and Zn doped Hydroxyapatite derived from Bio and synthetic sources

To meet everyday food requirements with an ever-increasing population in the world, a huge amount of Eggshell waste is given rise everywhere from household kitchens to various food processing units. Eggshell contains a large amount of calcium compound. In this study, two different kinds of Hydroxyapatite (HAp), one from different laboratory reagents and the other one from eggshell have been synthesized. 3% Titanium and Zinc doped variants have also been made for both kinds of Hydroxyapatite. The prepared powder samples were calcined at 800°C and pellets were formed by applying pressure. A comparative analysis of these two different sourced products has been made by analyzing physical properties (Density, apparent porosity, hardness), a functional group study (FTIR). The elemental configuration of all materials was confirmed by the EDAX study. XRD analysis revealed the lattice parameters of the pure product has been suffered a little bit with the doping agents. SEM images showed a significant amount of porosity and nodular grains of HAp. Cytotoxic analysis and MTT assay established the non-toxic nature of all compounds, In vitro SBF study showed apatite layer formation above the pellet surfaces of different grades and Ti-doped samples gained the maximum amount of apatite.

Recovery of uranium from conversion production sludge by leaching with nitric acid and subsequent ion-exchange concentration

Physicochemical studies of the sludge of uranium conversion production were carried out to determine the possibility of its processing and return of uranium to the nuclear fuel cycle. It has been established that the sludge was mainly represented by calcium compounds: CaSO4·2H2O (60.1 wt%), CaCO3 (25.1 wt%), CaF2 (13.7 wt%), and silicon dioxide (1.2 wt%). The content of uranium in the sludge was 0.15 wt%. It was shown that it was possible to achieve high degrees of uranium extraction from the sludge using nitric acid as a leaching agent. The use of phosphorus-containing ion-exchanger Tulsion CH93 ensured the effective concentration of uranium from highly acidic pregnant leach solutions. The full dynamic exchange capacity achieved 15.7 kg m−3. The degree of uranium desorption by ACBM (ammonium carbonate/bicarbonate mixture) solutions was 83%. The final product was ammonium uranyl phosphate hydrate NH4UO2PO4∙3H2O with a uranium content of 52.5 wt%.