Strontium Salt Research Articles

Sr-doped carbon matrices for use as electrodes in autonomous electrical energy sources

Relevance. The need to create new safe energy sources that can meet the needs of production and medicine where the use of traditional energy sources is impossible or unprofitable. Such sources may include radioisotope power sources, in which energy production is ensured by the natural decay of radionuclides. The most important components of current sources such as supercapacitors are electrode materials, the characteristics of which determine the electrophysical characteristics of radioisotope sources. This work proposes a method for synthesizing a carbon matrix doped with Sr for use as electrodes of radioisotope power sources. Aim. Development, mastery and optimization of a method for synthesizing electrodes of radioisotope power sources based on carbon materials doped with the Sr-90 radioisotope. Objects. Carbon material doped with a radioisotope simulant Sr-90 (Sr stable). Carbon matrices were obtained by carbonizing a resorcinol-formaldehyde resin doped with a stable strontium salt. Methods. Scanning electron microscopy, low-temperature adsorption-desorption of nitrogen, cyclic voltammetry, galvanostatic charge-discharge, impedance microscopy. Results. A carbon matrix doped with a stable strontium isotope was synthesized by the method of semi-carbonization followed by physical activation with carbon dioxide. The structure, porosity and electrochemical characteristics of the material were studied. It was established that physical activation has a positive effect on the development of the specific surface area and mesoporosity of the samples of the synthesized matrix, as a result of which its electrochemical characteristics are improved. The method of physical activation is proposed as the most preferable for the synthesis of a carbon matrix doped with strontium isotopes for use as electrodes of radioisotope power supplies.

Features of adsorption phenomena in strontium salt solutions in the presence of some cavitands of cucurbituril family

The influence of the electrolyte nature and cation charge on the adsorption properties of cucurbit[6]uril supramolecular complexes are established and discussed. The results show the narrowing of the adsorption potential region of these complexes with increasing cation charge, and the possibility to form an adsorbate layer of supramolecular cations associated with surface-active electrolyte anions at the positive boundary of the adsorption potential region.

COORDINATION POLYMER OF STRONTIUM (II) BASED ON PHTHALIC ACID AND PYRAZINE ADDUCT

The coordination polymer of Sr (II), with the chemical formula of {SrL1 (L2)0.5·(H2O)0.36}n (L1 = phthalic acid anion and L2 = pyrazine), have been synthesized by the interaction of sodium phthalate with a water-soluble strontium salt and pyrazine in the aqueous medium with further evaporation of an aqueous solution and characterized by IR spectroscopic, elemental, single-crystal X-ray diffraction and thermal analysis. The results of XRD analysis showed that the synthesis product has a single-phase and is well-identified by means: 12.73; 11.41; 9.04 showing that the unit cell parameters of this compound are approximately equal to a = 12.74, b = 11.41, and c = 9.04 Å. IR spectroscopic studies showed that phthalate anion in polymer acts as a chelate and bridging ligand. Thermographic analysis showed that the polymer is stable up to a temperature of ̴ 2000С

To Determine the Efficacy of Strontium Ranelate in the Healing of Surgically Fixed Tibial Diaphyseal Fractures Using Intramedullary Devices (Nails) in Tertiary Care Hospital

Introduction: Strontium ranelate is a strontium salt of ranelic acid that enhances bone healing by increasing the deposition of new bone-forming osteoblasts and reduces the function and number of bone-resorbing osteoclasts. Strontium ranelate acts via a dual mode of action with both bone-forming and bone-resorbing properties, and may therefore be beneficial in fracture healing. It is therefore promoted as a “dual-action bone agent. Objective: To determine the efficacy of strontium ranelate in the healing of surgically fixed tibial diaphyseal fractures using intramedullary devices (nails) in tertiary care hospital. Material and Methods: This descriptive case series study was done at the department of orthopedic surgery, Chandka medical college Larkana and was conducted for six months between 1st of July 2021 to 31st of December 2021. Total 184 patients with closed diaphyseal tibial fractures were included. All patients have undergone closed reduction and internal fixation using nail. Strontium ranelate as a single dose for a duration of three months was given. Final outcome i.e. efficacy was measured on the basis of clinical and radiological criteria. Descriptive statistics were calculated using SPSS. Stratification was done and the post-stratification chi-square test was applied. P-value ≤ 0.05 was taken as significant. Results: There were 118 were male and 66 were female. The mean age of study subjects was 34.18±9.80 years. The mean duration of fracture was 5.78±3.29 days. 49.5% were caused by fractures due to road traffic accidents. The efficacy of strontium ranelate was found in 67.9%. The significant association of efficacy of strontium ranelate was observed with age and duration of fracture. Conclusion: Significant efficacy of strontium ranelate in the healing of surgically fixed tibial diaphyseal fractures on clinical and radiological assessment was observed.

PH-responsive strontium nanoparticles for targeted gene therapy against mammary carcinoma cells

Genetic intervention via the delivery of functional genes such as plasmid DNA (pDNA) and short-interfering RNA (siRNA) offers a great way to treat many single or multiple genetic defects effectively, including mammary carcinoma. Delivery of naked therapeutic genes or siRNAs is, however, short-lived due to biological clearance by scavenging nucleases and circulating monocytes. Low cellular internalization of negatively-charged nucleic acids further causes low transfection or silencing activity. Development of safe and effectual gene vectors is therefore undeniably crucial to the success of nucleic acid delivery. Inorganic nanoparticles have attracted considerable attention in the recent years due to their high loading capacity and encapsulation activity. Here we introduce strontium salt-based nanoparticles, namely, strontium sulfate, strontium sulfite and strontium fluoride as new inorganic nanocarriers. Generated strontium salt particles were found to be nanosized with high affinity towards negatively-charged pDNA and siRNA. Degradation of the particles was seen with a drop in pH, suggesting their capacity to respond to pH change and undergo dissolution at endosomal pH to release the genetic materials. While the particles are relatively nontoxic towards the cells, siRNA-loaded SrF2 and SrSO3 particles exerted superior transgene expression and knockdown activity of MAPK and AKT, leading to inhibition of their phosphorylation to a distinctive extent in both MCF-7 and 4T1 cells. Strontium salt nanoparticles have thus emerged as a promising tool for applications in cancer gene therapy.

Room temperature synthesis and Raman spectral evidence of carbon bond ranelate–gold nanoparticles

AbstractRanelate ions, employed in the past as strontium salt for the treatment of osteoporosis, exhibit a rather interesting chemistry associated with a central thiophene ring encompassing two carboxylic groups, a cyanonitrile substituent, and a nitrile diacetate group. In spite of their unfavorable reduction potentials, around 1.26 V, they react very rapidly with HAuCl4 at room temperature, leading to decarboxylation at the C5 position in order to generate gold nanoparticles strongly stabilized by Au–C bonds. The reactions were elucidated by electrospray ionization mass spectrometry, ligand exchange kinetics, and by means of the surface‐enhanced Raman scattering effect. The gold nanoparticles were further characterized based on transmission electron microscopy and CytoViva hyperspectral microscopy.

Effect of SrR delivery in the biomarkers of bone regeneration during the in vitro degradation of HNT/GN coatings prepared by EPD

Among strontium-based drugs, the Strontium ranelate (SrR) is a divalent strontium salt of ranelic acid which has an overall effect over the bone microarchitecture improvement. However, some findings reveal that the SrR affects in an opposite manner to the cell proliferation and osteoblastic differentiation, based on its concentration. Consequently, its release should be controlled. The incorporation of Halloysite nanotubes (HNT) as nanocarriers of SrR, into gelatine (GN) coatings, tailors the release of this anabolic bone-forming and anti-catabolic agent to stimulate bone growth. In fact, as-prepared GN/HNT-SrR coatings release 100 % SrR in phosphate buffered saline (PBS) within 21 days, and cellular studies of the nanocomposite coatings (MTT, Alkaline Phosphatase activity (ALP) and Calcium deposition assay) confirm the valuable bio-performance of these composite coatings to enhanced bone regeneration. In the present manuscript, suspensions with HNT/GN weight ratio of 0.5 are formulated to coat AISI 316 L stainless steel foils by Electrophoretic Deposition (EPD). Zeta potential determination is used to stablish the drug loading (HNT-SrR) by electrostatic interaction, as well as to optimize the dispersion of bare HNT and HNT SrR-loaded in a GN aqueous solution. Polyethilenimnine (PEI) is used as stabilizer to buffer the suspension media, assure cargo-drug dispersion and sequential release, while the thermal gelling of the suspension controls and step up the coating formation during EPD.

Facile synthesis of ultrafine and high purity spherical strontium carbonate via gas-liquid reaction

In this work, a simple gas-liquid precipitation reaction was developed to fabricate spherical strontium carbonate (SrCO3) particles using strontium hydroxide (Sr(OH)2), carbon dioxide (CO2) and ethylene diaminetetraacetic acid strontium salt (EDTA-Sr) as raw materials. The effects of the concentration of EDTA-Sr and Sr(OH)2, airflow rate of CO2 and reaction temperature on the morphology of SrCO3 were investigated. The results showed that spherical SrCO3 particles can be formed when the concentration of EDTA-Sr reached 0.02 M as well as that of Sr(OH)2 was less than 0.1 M. The airflow rate of CO2 gas had little effect on the spherical morphology, and SrCO3 microsphere with good dispersion could be obtained when the reaction temperature reached 50 °C. Under the optimal conditions ([EDTA-Sr] = 0.02 M, [Sr(OH)2] = 0.1 M, 50 °C, [CO2] = 1 l min−1), high purity spherical SrCO3 particles with diameter of 200–800 nm can be easily obtained. Finally, the growth mechanism of spherical SrCO3 has been preliminarily presented, which indicated that EDTA-Sr is an excellent structure-directing agent for forming pherical SrCO3 particles. Our work offers an effective method for large-scale production of high purity spherical SrCO3.

A Rock Guide to Fireworks

Before a firework was red, it was a strontium salt waiting for its moment.

Development of novel inorganic strontium nanoparticles for delivery of pDNA and siRNA to breast cancer cell

Event Abstract Back to Event Development of novel inorganic strontium nanoparticles for delivery of pDNA and siRNA to breast cancer cell ATHIRAH BAKHTIAR1*, Md Ezharul H. Chowdhury2, Iekhsan Othman3 and Anuar Zaini3 1 Faculty of Pharmacy, Mahsa University, Malaysia 2 Monash University Malaysia, Malaysia 3 Monash University, Australia Background Recent studies have been focused on developing smart nanoparticles for efficient delivery of transgenes and siRNAs into cancerous cells of an animal model through active and passive targeting. Precipitation reaction is one of the facile and convenient ways to generate inorganic strontium nanoparticles, in which an insoluble salt is formed after mixing two water-soluble salts. Advantages in comparison with other methods include requiring only simple equipment, ability to prepare and control particle size and composition in near ambient temperature and pressure. The approach would pave a new way for facile, low toxicity and large-scale synthesis of inorganic nanoparticles with well-controlled dimensions and properties. Methods The study involved the formation of 5 different types of inorganic strontium nanocrystals via precipitation reactions, with various observational studies involving pH, temperature, salt concentration and time of incubation. Strontium particle sizes were determined using zetasizer and scanning electron microscope prior to binding studies. The nanoparticles were then subjected to various cellular studies including cellular uptake and cytotoxicity studies through incorporation of p53 and MAPK siRNA, forming gene-nanoparticle complexes onto human and mice mammary carcinoma cells, MCF-7 and 4T1 cells, respectively. Unloaded strontium nanoparticles formed were also observed for toxicity effect against both cells. Results Studies showed that strontium fluoride and strontium carbonate were smaller in size in comparison to other strontium salt particles, averaging in 100-300nm in diameter. Additionally, cellular studies revealed that gene-loaded strontium sulfite and strontium fluoride were responsible for greater cytotoxicity effect, in comparison naked gene treatment. Low toxicity effect was seen with unloaded strontium nanoparticles. Studies were compared against established inorganic carbonate apatite nanoparticles. Conclusion Nano-sized strontium particles showed great potential to be applied for in vivo studies, ideally seen with strontium sulfite and strontium fluoride, via the gene delivery system in the cellular level. Keywords: breast cancer, pDNA delivery, siRNA, Strontium, Nanoparticles Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Poster Presentation Topic: Cancer Citation: BAKHTIAR A, Chowdhury MH, Othman I and Zaini A (2019). Development of novel inorganic strontium nanoparticles for delivery of pDNA and siRNA to breast cancer cell. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00137 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 Oct 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. ATHIRAH BAKHTIAR, Faculty of Pharmacy, Mahsa University, Bandar Saujana Putra, Selangor, 42610, Malaysia, athirahbakhtiar@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers ATHIRAH BAKHTIAR Md Ezharul H Chowdhury Iekhsan Othman Anuar Zaini Google ATHIRAH BAKHTIAR Md Ezharul H Chowdhury Iekhsan Othman Anuar Zaini Google Scholar ATHIRAH BAKHTIAR Md Ezharul H Chowdhury Iekhsan Othman Anuar Zaini PubMed ATHIRAH BAKHTIAR Md Ezharul H Chowdhury Iekhsan Othman Anuar Zaini Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Deterioration of the mechanical properties of calcium phosphate cements with Poly (γ-glutamic acid) and its strontium salt after in vitro degradation.

The mechanical reliability of calcium phosphate cements has restricted their clinical application in load-bearing locations. Although their mechanical strength can be improved using a variety of strategies, their fatigue properties are still unclear, especially after degradation. The evolutions of uniaxial compressive properties and the fatigue behavior of calcium phosphate cements incorporating poly (γ-glutamic acid) and its strontium salt after different in vitro degradation times were investigated in the present study. Compressive strength decreased from the 61.2±5.4MPa of the original specimen, to 51.1±4.4, 42.2±3.8, 36.8±2.4 and 28.9±3.2MPa following degradation for one, two, three and four weeks, respectively. Fatigue life under same loading condition also decreased with increasing degradation time. The original specimens remained intact for one million cycles (run-out) under a maximum stress of 30MPa. After degradation for one to four weeks, the specimens were able to withstand maximum stress of 20, 15, 10 and 10MPa, respectively until run-out. Defect volume fraction within the specimens increased from 0.19±0.021% of the original specimen to 0.60±0.19%, 1.09±0.04%, 2.68±0.64% and 7.18±0.34% at degradation time of one, two, three and four weeks, respectively. Therefore, we can infer that the primary cause of the deterioration of the mechanical properties was an increasing in micro defects induced by degradation, which promoted crack initiation and propagation, accelerating the final mechanical failure of the bone cement. This study provided the data required for enhancing the mechanical reliability of the calcium phosphate cements after different degradation times, which will be significant for the modification of load-bearing biodegradable bone cements to match clinical application.

Spontaneous reossification of the sella in transsphenoidal reoperation associated with strontium ranelate.

Spontaneous reossification of the sellar floor after transsphenoidal surgery has been rarely reported. Strontium ranelate, a divalent strontium salt, has been shown to increase bone formation, increasing osteoblast activity. We describe an unusual case of a young patient with Cushing’s disease who was treated with strontium ranelate for low bone mass who experienced spontaneous sellar reossification after transsphenoidal surgery. A 21-year-old male presented with Cushing’s features. His past medical history included delayed puberty diagnosed at 16 years, treated with testosterone for 3 years without further work-up. He was diagnosed with Cushing’s disease initially treated with transsphenoidal surgery, which was not curative. The patient did not come to follow-up visits for more than 1 year. He was prescribed strontium ranelate 2 g orally once daily for low bone mass by an outside endocrinologist, which he received for more than 1 year. Two years after first surgery he was reevaluated and persisted with active Cushing’s disease. Magnetic resonance image revealed a left 4 mm hypointense mass, with sphenoid sinus occupation by a hyperintense material. At repeated transsphenoidal surgery, sellar bone had a very hard consistency; surgery was complicated and the patient died. Sellar reossification negatively impacted surgery outcomes in this patient. While this entity is possible after transsphenoidal surgery, it remains unclear whether strontium ranelate could have affected sellar ossification.Learning points:Delayed puberty can be a manifestation of Cushing’s syndrome. A complete history, physical examination and appropriate work-up should be performed before initiating any treatment.Sellar reossification should always be taken into account when considering repeated transsphenoidal surgery. Detailed preoperative evaluation of bony structures by computed tomography ought to be performed in all cases of reoperation.We speculate if strontium ranelate may have affected bone mineralization at the sellar floor. We strongly recommend that indications for prescribing this drug should be carefully followed.

Modification of calcium phosphate cement with poly (γ-glutamic acid) and its strontium salt for kyphoplasty application

To meet the requirements of minimally invasive surgical treatments for osteoporotic vertebral compression fracture, various strategies have been proposed to enhance the properties of calcium phosphate cement (CPC). Here, a new strategy was developed by incorporating poly (γ-glutamic acid) (γ-PGA) and its strontium salt into the formulation of alpha tricalcium phosphate (α-TCP)-based CPC. Effects of γ-PGA on the injectability, cohesion, setting times, mechanical compressive strengths and cytocompatibility were systematically studied. Results showed that the injectability, cohesion and setting times were considerably improved by introducing γ-PGA into the CPC. Moreover, after setting for 7days, the compressive strengths increased from 14.6±1.4MPa for pure CPC to 35.3±1.7MPa for CPC with 8.9wt% γ-PGA and further to 61.2±5.4MPa for CPC with 8.9wt% γ-PGA combined with its strontium salt. In vitro osteoblast proliferation tests showed that the group of CPC modified by γ-PGA and its strontium salt had better cytocompatibility than the pure CPC group. All results suggest that optimal properties were obtained for the cement with 8.9wt% γ-PGA added to its solid phases and using strontium salt as the reactive liquid phase, making it as a promising candidate for application in kyphoplasty.

Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo.

In this manuscript, we fabricated amorphous strontium-polyphosphate microparticles ("Sr-a-polyP-MP") and studied their effects on bone mineral formation in vitro as well as in vivo. In vitro, those particles substantially increased the expression of the genes encoding for alkaline phosphatase, the bone morphogenetic protein 2 and the mineralization. In vivo, the "Sr-a-polyP-MP" packed into PLGA microspheres and implanted into critical-size calvarial defects in rats resulted in a speeded up of the healing/mineralization of the bone defect. Those properties qualify Sr-a-polyP as a suitable biomaterial for bone regenerative implants.

New route for preparation SrTiO3 nanoparticles with different acids and its photocatalyst application

Strontium titanate (SrTiO3) nanoparticles were effectively synthesized by a new route using strontium salt as novel strontium nitrate tetrahydrate source and tetra-n-butyl titanate (TNBT) as titanium source. The effect different acids such as salicylic acid, oxalic acid, and cinnamic acid on the morphology and size of strontium titanate was investigated. Alternating gradient force magnetometer illustrated ferromagnetic behaviour of strontium titanate nanoparticles. The as-synthesized strontium titanate nanoparticles were characterized by X-ray microanalysis, scanning electron microscopy, diffuse reflectance spectroscopy (UV–Vis), and energy dispersive X-ray diffraction. The photocatalytic behaviour of strontium titanate nanoparticles was evaluated using the degradation of methyl orange under ultraviolet light irradiation.

Synthesis, characterization, and of investigation magnetic and photocatalytic property of SrWO4 nanoparticles

Pure SrWO4 nanoparticles were successfully synthesized by sonochemical method with the aid of strontium salt and sodium tungstate dihydrate in water without adding surfactant, capping agent or template. To the best of authors’ knowledge, it is the first time that SrWO4 was synthesized by ultrasonic method. The structural, morphological and optical properties of as-obtained products were characterized by techniques such as X-ray diffraction, scanning electron microscopy, energy dispersive X-ray microanalysis, and ultraviolet–visible spectroscopy. The magnetic properties of as-prepared SrWO4 nanoparticles were also investigated with vibrating sample magnetometer. The photocatalytic properties of as-synthesized SrWO4 were evaluated by degradation of methyl orange as water contaminant.

Synthesis of crystalline perovskite-structured SrTiO3 nanoparticles using an alkali hydrothermal process

We report an experimental route for synthesizing perovskite-structured strontium titanate (SrTiO3) nanocubes using an alkali hydrothermal process at low temperatures without further heating. Furthermore, we studied the influence of heating time (at 180°C) on the crystallinity, morphology, and perovskite phase formation of SrTiO3. The SrTiO3 powder, which is formed via nanocube agglomeration, transforms into cubic particles with a particle size of 120–150 nm after 6 h of hydrothermal sintering. The crystallinity and percentage of the perovskite phase in the product increased with heating time. The cubic particles contained 31.24at% anatase TiO2 that originated from the precursor. By varying the weight ratio of anatase TiO2 used to react with the strontium salt precursor, we reduced the anatase-TiO2 content to 18.8at%. However, the average particle size increased when the anatase-TiO2 content decreased.

HOT AEROSOL FIRE EXTINGUISHING AGENTS AND THE ASSOCIATED TECHNOLOGIES: A REVIEW

Since the phase out of Halon extinguishers in the 1980s, hot aerosol fire suppression technology has gained much attention. Unlike traditional inert gas, foam, water mist and Halon fire suppression agents, hot aerosol fire extinguishing agents do not need to be driven out by pressurized gases and can extinguish class A, B, C, D and K fires at 30 to 200 g/m3. Generally, hot aerosol fire extinguishing technology has developed from a generation I oil tank suppression system to a generation III strontium salt based S-type system. S-type hot aerosol fire extinguishing technology greatly solves the corrosion problem of electrical devices and electronics compared to potassium salt based generation I & II hot aerosol fire extinguishing technology. As substitutes for Halon agents, the ODP and GWP values of hot fire extinguishing aerosols are nearly zero, but those fine aerosol particles can cause adverse health effects once inhaled by human. As for configurations of hot aerosol fire extinguishing devices, fixed or portable cylindrical canisters are the most common among generation II & III hot aerosol fire extinguishers across the world, while generation I hot aerosol fire suppression systems are integrated with the oil tank as a whole. Some countries like the U.S., Australia, Russia and China, etc. have already developed standards for manufacturing and quality control of hot aerosol fire extinguishing agents and norms for hot aerosol fire extinguishing system design under different fire protection scenarios. Coolants in hot aerosol fire suppression systems, which are responsible for reducing hot aerosol temperature to avoid secondary fire risk are reviewed for the first time. Cooling effects are generally achieved through vaporization and endothermic chemical decomposition of coolants. Finally, this review discussed areas applying generation I, II or III hot aerosol fire suppression technologies. The generation III hot aerosol fire extinguishing system is most applicable, especially in areas involving delicate electrical and electronic equipments. Nonetheless, developing a much cleaner, non-corrosive and highly efficient hot aerosol fire suppression system is still needed.

Effect of strontium oxide on the formation mechanism of dicalcium silicate with barium oxide and sulfur trioxide

Belite-barium calcium sulfoaluminate cement is a new type of cement characterised by low energy consumption and low carbon dioxde emissions, but the slow hydration of the belite phase leads to a slow mechanical property gain at early ages compared with ordinary Portland cement. A doping technique has been proposed as one option to promote its reactivity. Strontium slag, a kind of chemical industrial waste produced from the manufacture of strontium salt, has a high level of emissions in China. In this study, the influence of strontium oxide on the formation mechanism of dicalcium silicate with barium oxide and sulfur trioxide, which are both in excess in belite-barium calcium sulfoaluminate cement clinker, is investigated. Results show that strontium oxide accelerates the decomposition process of calcium carbonate, and its final decomposition temperature can be lowered by 67°C. Strontium oxide decreases the formation rate of dicalcium silciate at the same temperature, but the amount of total dicalcium silicate formed can still be as high as 94·5 wt% at 1350°C. Moreover, it is revealed that strontium oxide plays a significant role in stabilising β-dicalcium silicate, and reduces γ-dicalcium silicate by about 40%. This study could lead to environmental benefits and cement performance improvement.

The synthesis of novel powder master alloys for the modification of primary and eutectic silicon crystals

The effect of the high-energy synthesis of powder mixtures of aluminium granules, ferrophosphorous (Fe2P) and strontium salt (SrCO3) in a planetary mill was investigated on the structure of the resulting materials. Al–8Fe–2P, Al–10Sr and Al–10Sr–1P master alloys were synthesised, and the efficiency of these new alloys was demonstrated in the modification of an eutectic silicon in Al–12Si alloys and the complex modification of Al–18Si alloys.