Artículos de revistas: "Magnesium phosphates"

1

Gu, Xiang, Yan Li, Chao Qi y Kaiyong Cai. "Biodegradable magnesium phosphates in biomedical applications". Journal of Materials Chemistry B 10, n.º 13 (2022): 2097–112. http://dx.doi.org/10.1039/d1tb02836g.

Texto completo

Resumen

This review comprehensively summarizes the state-of-the-art progress made in magnesium phosphate-based biomaterials, including nanostructured magnesium phosphates and magnesium phosphate-based cements, ceramics, scaffolds, coatings and so on, as well as their biomedical applications in nanomedicine and tissue engineering.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Kazakova, Gilyana, Tatiana Safronova, Daniil Golubchikov, Olga Shevtsova y Julietta V. Rau. "Resorbable Mg2+-Containing Phosphates for Bone Tissue Repair". Materials 14, n.º 17 (26 de agosto de 2021): 4857. http://dx.doi.org/10.3390/ma14174857.

Texto completo

Resumen

Materials based on Mg2+-containing phosphates are gaining great relevance in the field of bone tissue repair via regenerative medicine methods. Magnesium ions, together with condensed phosphate ions, play substantial roles in the process of bone remodeling, affecting the early stage of bone regeneration through active participation in the process of osteosynthesis. In this paper we provide a comprehensive overview of the usage of biomaterials based on magnesium phosphate and magnesium calcium phosphate in bone reconstruction. We consider the role of magnesium ions in angiogenesis, which is an important process associated with osteogenesis. Finally, we summarize the biological properties of calcium magnesium phosphates for regeneration of bone.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Possenti, Elena, Claudia Conti, G. Diego Gatta, Marco Realini y Chiara Colombo. "Diammonium Hydrogenphosphate Treatment on Dolostone: the Role of Mg in the Crystallization Process". Coatings 9, n.º 3 (4 de marzo de 2019): 169. http://dx.doi.org/10.3390/coatings9030169.

Texto completo

Resumen

The diammonium hydrogenphosphate (DAP, (NH4)2HPO4) reaction with calcite has been extensively investigated. The availability of free calcium ions in the reaction environment has been acknowledged as a crucial factor in the crystallization of calcium phosphates with a high (hydroxyapatite, Ca/P 1.67) or low Ca/P molar ratio (dicalcium phosphate dihydrate, Ca/P 1.00; octacalcium phosphate, Ca/P 1.33). On the contrary, no data are available on the DAP interaction at room temperature with dolomite in terms of reaction mechanism and composition of the reaction products. Here, a multi-analytical approach based on scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDS) and X-ray powder diffraction before and after heating treatments is proposed to explore how the formation of calcium phosphates occur on Mg-enriched substrates and if the presence of magnesium ions during the reaction influences the crystallization process of calcium phosphates. The DAP reaction with polycrystalline dolomite gives rise to the formation of struvite and of poorly crystalline hydroxyapatite. Calcium and magnesium ions mutually interfered in the crystallization of magnesium and calcium phosphates, respectively, whose effects influenced the properties (size, micro-morphology, composition and crystallinity) of the newly-formed phases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Isaicheva, Lyudmila Anatol'evna, Natal'ya Mikhailovna Trepak, Arlen Leonidovich L'vov y Ivan Alekseevich Kazarinov. "Corrosion and Еlectrochemical Behaviour of Magnesium and Magnesium-Lithium Alloys in Phosphoric Acid Media". Electrochemical Energetics 12, n.º 3 (2012): 124–28. http://dx.doi.org/10.18500/1608-4039-2012-12-3-124-128.

Texto completo

Resumen

The corrosion and electrochemical behavior of magnesium and the MA 21 magnesium-lithium alloys in solutions of moderately acidic phosphates with various additives was studied. The inhibiting effect of nitrate and fluoride ions on the anode dissolution of these objects was revealed. Features of the electrochemical dissolution of magnesium and the magnesium-lithium alloys in nitrate phosphate solutions with fluoride ions caused by their activation-passivation competition have been noted. Distinctive features of the electrochemical behavior of the magnesium-lithium alloys in comparison with pure magnesium in nitrate phosphate fluoride solutions due to their structural and phase specifics have been established.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Yoshida, Katsumi, Hideki Hyuga, Naoki Kondo y Hideki Kita. "Improvement of Oxidation Resistance of Graphite Powder Treated with Phosphate". Key Engineering Materials 352 (agosto de 2007): 133–36. http://dx.doi.org/10.4028/www.scientific.net/kem.352.133.

Texto completo

Resumen

Graphite powder was treated with lanthanum, aluminum and magnesium phosphate solution, and oxidation resistance of the obtained graphite powder was evaluated. Oxidation starting temperature and oxidation completion temperature of graphite powder treated with various phosphates were 50-100oC higher than those of as-received graphite powder. Graphite powder treated with small amount of lanthanum phosphate exhibited the higher oxidation starting temperature than graphite powder treated with aluminum and magnesium phosphates. LaP5O14 would partially exited on graphite powder, and protect the edge carbon atoms of graphite and reduce the reactivity of carbon atoms toward oxygen, resulting in improving the oxidation resistance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Kazakova, G. K., T. V. Safronova y T. B. Shatalova. "Ceramics based on powders synthesized from ammonium hydrophosphate and acetates of calcium and magnesium". Materials Science, n.º 4 (20 de abril de 2021): 33–40. http://dx.doi.org/10.31044/1684-579x-2021-0-04-33-40.

Texto completo

Resumen

Ceramics the phase composition of which included tricalcium phosphate, calcium magnesium ortophosphate and magnesium pyrophosphate has been produced from nanosized powders synthesized by chemical deposition from 1M aqueous solutions of ammonium hydrogen phosphate and calcium and / or magnesium acetates. According to XRD analysis the phase composition of the powder synthesized from calcium acetate included calcium hydroxyapatite Ca5(PO4)3(OH), octacalcium phosphate Ca8H2(PO4)6·5H2O and brushite CaHPO4·2H2O. The phase composition of the powder synthesized from magnesium acetate included struvite MgNH4PO4·6H2O. And the phase composition of the powder synthesized from solution containing calcium and magnesium acetates at the cation ratio Са: Mg = 9: 1 included hydroxyapatite Ca5(PO4)3(OH), whitlockite Ca18Mg2H2(PO4)14, and struvite MgNH4PO4·6H2O. Ceramic materials containing the bioresorbable and biocompatible phases of calcium and / or magnesium phosphates can be used to make bone implants for treatment of bone tissue defects. Keywords: tricalcium phosphate, calcium magnesium orthophosphate, magnesium pyrophosphate, whitlockite, octacalcium phosphate, hydroxyapatite, brushite, struvite, ceramics.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Ding, Zhu, Ming Zhang, Bi Qin Dong, Wei Liu y Han Lu. "Phosphate Bonding: A New Method for Using Large Volume of Fly Ash". Key Engineering Materials 539 (enero de 2013): 225–29. http://dx.doi.org/10.4028/www.scientific.net/kem.539.225.

Texto completo

Resumen

Magnesium phosphate cements (MPC) with larger volume of fly ash were studied in the present work. Dead burned magnesia, phosphates and fly ash were the components of MPC. The volume of fly ash in MPC was 70%, 75% and 80%, respectively. Three phosphates, monosodium phosphate (MSP), monopotassium phosphate (MPP) and monoammonium phosphate (MAP) were used. Compressive strength of the three MPC mortars with different fly ash content was determined. Results show that the compressive strength reduced with the proportion increase of fly ash, increased with the curing time. After cured 28 days in the lab air, the compressive strength of cement mortar can reach 14MPa, when the fly ash dosage was 80% by weight of cement. The reaction product is struvite of potassium (KMgPO4•6H2O) in potassium phosphate based MPC, and hydrated sodium phosphate (Na2HPO4•17H2O) in sodium phosphate based MPC. The results indicate that MPC has capacity to bond large volume of fly ash. A new way to utilize fly ash in a large scale can be realized by phosphate bonding.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Driessens, F. C. M., M. G. Boltong, R. Wenz y J. Meyer. "Calcium Phosphates as Fillers in Struvite Cements". Key Engineering Materials 284-286 (abril de 2005): 161–64. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.161.

Texto completo

Resumen

Struvite or magnesium ammonium phosphate MgNH4PO4 has been proposed as active component in setting surgical cements. The usual formulation is one in which the magnesium component in the powder is either magnesium hydrogen phosphate trihydrate or trimagnesium phosphate or a mixture of these two compounds. As the cement liquid a concentrated solution of diammonium phosphate is taken. To make the cement attractive as a bone substitute material a calcium phosphate filler is generally incorporated. Thus such materials are a type of pseudo calcium phosphate cements. This study was intended to find out which calcium phosphate and which magnesium compound are the most suitable. In the first series of experiments a mixture of 12 g Mg3(PO4)2 and 4 g MgHPO4.3H2O was used as the magnesium component in the powder. To that powder 30 g of either precipitated hydroxyapatite PHA or CaHPO4 or CaHPO4.H2O or b-TCP or a-TCP was added. The cement liquid was a 3.5 M solution of (NH4)2HPO4. At specific liquid/powder ratios L/P suitable setting times were obtained for the different formulations. However, the compressive strengths after immersion of the cements in 0.9% saline solution at 37°C varied over a large range. The best formulation was that with a-TCP which reached a compressive strength of 57 MPa after 18 h of immersion. In the second series of experiments 20 g of Mg3(PO4)2 was used as the magnesium component in the powder. Again 30 g of either of the above mentioned calcium phosphates was used as filler and again a 3.5 M solution of (NH4)2HPO4 was used as the cement liquid. At the appropriate L/P ratios the respective setting times were longer than in the first series of experiments but all five formulations appeared to result in good compressive strengths varying from 41 MPa for the formulation with b-TCP to 67 MPa for the formulation with PHA. In the third series of experiments 30 g a-TCP was taken as the calcium phosphate in the powder. As magnesium components mixtures of Mg3(PO4)2.8H2O and MgHPO4.3H2O and Mg3(PO4)2 were used. Again the cement liquid consisted of a 3.5 M solution of (NH4)2HPO4. The formulations with Mg3(PO4)2.8H2O had the shortest setting times and the lowest compressive strengths, whereas those with Mg3(PO4)2 had the longest setting times and the highest compressive strengths. Therefore, it is advantageous to use Mg3(PO4)2 as the magnesium component.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Nabiyouni, Maryam, Yufu Ren y Sarit B. Bhaduri. "Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites". Materials Science and Engineering: C 52 (julio de 2015): 11–17. http://dx.doi.org/10.1016/j.msec.2015.03.032.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Seel, F., K. P. Klos, D. Recktenwald y J. Schuh. "Zur Frage der nicht-enzymatischen Bildung von kondensierten Phosphaten unter präbiotischen Bedingungen/ Non-Enzymatic Formation of Condensed Phosphates under Prebiotic Conditions". Zeitschrift für Naturforschung B 41, n.º 7 (1 de julio de 1986): 815–24. http://dx.doi.org/10.1515/znb-1986-0704.

Texto completo

Resumen

AbstractOne of the problems of chemical evolution on the primitive Earth is the question of the possibility of a non-enzymatic spontaneous condensation o f phosphoric acid and hydrogen phosphates to yield polyphosphoric acids and polyphosphates in aqueous system s, by means of which phosphorus might have entered into early metabolisms. The extra- or intra-cellular formation of magnesium diphosphate under geologically plausible hydrothermal conditions from either magnesium hydrogen phosphates or calcium phosphates in media has been demonstrated.

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Lothenbach, Barbara, Biwan Xu y Frank Winnefeld. "Thermodynamic data for magnesium (potassium) phosphates". Applied Geochemistry 111 (diciembre de 2019): 104450. http://dx.doi.org/10.1016/j.apgeochem.2019.104450.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Sader, Marcia, Denisar Ismério, Mônica C. Andrade, Gloria D. Soares, Ivan N. Bastos y Gustavo M. Platt. "Characterization and Dissolution Dynamics of Tricalcium Phosphates in Acidified Solution". Journal of Biomimetics, Biomaterials and Tissue Engineering 18 (diciembre de 2013): 61–71. http://dx.doi.org/10.4028/www.scientific.net/jbbte.18.61.

Texto completo

Resumen

Bioceramics used in biomedical applications must exhibit specific behaviors. In scaffolds, for instance, the degradability of bioceramics is important to allow the cell ingrowth. Therefore, the dissolution of calcium phosphates increases the ionic concentrations around the interface implant–bone, favoring a more rapid bone apposition to the graft surface. The dissolution takes place under static or dynamic conditions, but the latter is usually not performed under rigorous hydrodynamic control. In the present work, two bioceramics, β-tricalcium phosphate and β-tricalcium phosphate substituted by magnesium, were produced by pressing and sintering to form disks. They were characterized by XRD, Raman, ICP, SEM, AFM and photometric test. The influence of chemical composition in the dissolution test was conducted through strict control of the hydrodynamic conditions. The disks were rotating in a precise speed, in order to produce a dissolution under the well-controlled mass transfer. Subsequently, the calcium release was evaluated in a simulated infectious environment using pH equals to circa 4. Thus, it was possible to evaluate the fraction of dissolution related to mass transfer or surface reactions for a large rotation speed range. The magnesium added to the bioceramic inhibits the total dissolution when compared to pure tricalcium phosphate, probably related to more dense and less soluble ceramic. Moreover, the mass transfer affects relatively less the magnesium tricalcium phosphate than pure tricalcium phosphate.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Crutchik, D. y J. M. Garrido. "Struvite crystallization versus amorphous magnesium and calcium phosphate precipitation during the treatment of a saline industrial wastewater". Water Science and Technology 64, n.º 12 (1 de diciembre de 2011): 2460–67. http://dx.doi.org/10.2166/wst.2011.836.

Texto completo

Resumen

Struvite crystallization (MgNH4PO4·6H2O, MAP) could be an alternative for the sustainable and economical recovery of phosphorus from concentrated wastewater streams. Struvite precipitation is recommended for those wastewaters which have high orthophosphate concentration. However the presence of a cheap magnesium source is required in order to make the process feasible. For those wastewater treatment plants (WWTP) located near the seashore magnesium could be economically obtained using seawater. However seawater contains calcium ions that could interfere in the process, by promoting the precipitation of amorphous magnesium and calcium phosphates. Precipitates composition was affected by the NH4+/PO43− molar ratio used. Struvite or magnesium and calcium phosphates were obtained when NH4+/PO43− was fixed at 4.7 or 1.0, respectively. This study demonstrates that by manipulating the NH4+/PO43− it is possible to obtain pure struvite crystals, instead of precipitates of amorphous magnesium and calcium phosphates. This was easily performed by using either raw or secondary treated wastewater with different ammonium concentrations.

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Sugiyama, Shigeru, Masahiko Yokoyama, Hisaaki Ishizuka, Ken-Ichiro Sotowa, Tahei Tomida y Naoya Shigemoto. "Removal of aqueous ammonium with magnesium phosphates obtained from the ammonium-elimination of magnesium ammonium phosphate". Journal of Colloid and Interface Science 292, n.º 1 (diciembre de 2005): 133–38. http://dx.doi.org/10.1016/j.jcis.2005.05.073.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Kuśnierczyk, Katarzyna y Michał Basista. "Recent advances in research on magnesium alloys and magnesium–calcium phosphate composites as biodegradable implant materials". Journal of Biomaterials Applications 31, n.º 6 (9 de julio de 2016): 878–900. http://dx.doi.org/10.1177/0885328216657271.

Texto completo

Resumen

Magnesium alloys are modern biocompatible materials suitable for orthopaedic implants due to their biodegradability in biological environment. Many studies indicate that there is a high demand to design magnesium alloys with controllable in vivo corrosion rates and required mechanical properties. A solution to this challenge can be sought in the development of metal matrix composites based on magnesium alloys with addition of relevant alloying elements and bioceramic particles. In this study, the corrosion mechanisms along with corrosion protection methods in magnesium alloys are discussed. The recently developed magnesium alloys for biomedical applications are reviewed. Special attention is given to the newest research results in metal matrix composites composed of magnesium alloy matrix and calcium phosphates, especially hydroxyapatite or tricalcium phosphate, as the second phase with emphasis on the biodegradation behavior, microstructure and mechanical properties in view of potential application of these materials in bone implants.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Xin, Yunchang, Kaifu Huo, Tao Hu, Guoyi Tang y Paul K. Chu. "Corrosion products on biomedical magnesium alloy soaked in simulated body fluids". Journal of Materials Research 24, n.º 8 (agosto de 2009): 2711–19. http://dx.doi.org/10.1557/jmr.2009.0323.

Texto completo

Resumen

Magnesium alloys are potential materials in biodegradable hard tissue implants. Their degradation products in the physiological environment not only affect the degradation process but also influence the biological response of bone tissues. In the work reported here, the composition and structure of the corrosion product layer on AZ91 magnesium alloy soaked in a simulated physiological environment, namely simulated body fluids (SBFs), are systematically investigated using secondary electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), and in situ monitoring of the corrosion morphology. Our results show that the corrosion product layer comprises mainly amorphous magnesium (calcium) phosphates, magnesium (calcium) carbonates, magnesium oxide/hydroxide, and aluminum oxide/hydroxide. The magnesium phosphates preferentially precipitate at obvious corrosion sites and are present uniformly in the corrosion product layer, whereas calcium phosphates nucleate at passive sites first and tend to accumulate at isolated and localized sites. According to the cross sectional views, the corrosion product layer possesses a uniform structure with thick regions several tens of micrometers as well as thin areas of several micrometers in some areas. Localized corrosion is the main reason for the nonuniform structure as indicated by the pan and cross-sectional views. The results provide valuable information on the cytotoxicity of magnesium alloys and a better understanding on the degradation mechanism of magnesium alloys in a physiological environment.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Cave, M. R., David Farrar y Adrian J. Wright. "Organic/Inorganic Hybrid Calcium Phosphate Biomaterials". Key Engineering Materials 361-363 (noviembre de 2007): 383–86. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.383.

Texto completo

Resumen

Calcium alkyl phosphates and their strontium and magnesium analogues were synthesised by the reaction of aqueous metal salts with a range of alkyl phosphates of varying chain length and were characterised by X-ray diffraction, thermogravimetric and FTIR analyses. These hybrid structures are based on alternating organic/metal phosphate regions and were found to exhibit a linear increase in interlayer separation upon increasing the length of the alkyl chain. Our analysis suggests a general formula for these phases of M(ROPO3).nH2O (where M = Ca, Sr, Mg and R = alkyl group), containing alkyl bilayers reminiscent of phospholipid bilayers found in biological membranes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Krokhicheva, P. A., M. A. Goldberg, D. R. Khairutdinova, A. S. Fomin, A. V. Kondratiev, A. S. Baikin, A. V. Leonov et al. "Cementing materials based on magnesium and calcium phosphates with sodium hyaluronate". Perspektivnye Materialy 9 (2022): 45–55. http://dx.doi.org/10.30791/1028-978x-2022-9-45-55.

Texto completo

Resumen

In the recent years, a magnesium-calcium phosphate materials are considered as an alternative to materials based on the calcium phosphates in the reconstructive surgery. The injectable bone cements have been particular interest for the minimally invasive surgical approaches. The aim of this work is considered to the creating and studying of the structural-phase state of cement materials based on the Newberite phase (MgHPO4·3H2O). The addition of a polymer - sodium hyaluronate in the cement fluid, based on a sodium phosphate solution, leeds to the increasing of the viscosity of the system, thereby increasing the cohesion of cement materials. The effect of addition sodium hyaluronate in the various concentrations on the phase composition, setting time, pH value, microstructure, injectability and strength properties of cement materials has been studied.

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Biliani, Styliani E., John Vakros y Ioannis D. Manariotis. "Screening of Raw and Modified Biochars from Food Processing Wastes for the Removal of Phosphates, Nitrates, and Ammonia from Water". Sustainability 14, n.º 24 (9 de diciembre de 2022): 16483. http://dx.doi.org/10.3390/su142416483.

Texto completo

Resumen

The aim of this work was to compare the performance of biochar from various food processing wastes of different origin for the removal of different nutrients from water. Eggshells (EGS), rice husk (RH), and coffee biochars were pyrolyzed at 400 and 800 °C and were examined for the removal of phosphates, nitrates, and ammonia nitrogen. The raw materials were also modified with magnesium chloride in order to investigate their sorption behavior. The highest sorption capacity (qmax) for phosphates and ammonium was observed with EGS pyrolyzed at 800 °C and was 11.45 mg PO43−-P/g and 11.59 mg NH3-N/g, while the highest nitrates sorption capacity was observed with the magnesium-modified RH pyrolyzed at 800 °C (5.24 mg NO3−-N). The modified EGS biochars pyrolyzed at 800 °C had almost the half the sorption capacity for phosphates and nitrates compared to the unmodified materials. The modification of RH pyrolyzed at 800 °C resulted in higher sorption capacity by 34 and 158% for phosphates and ammonium, respectively. The coffee raw and modified biochars were less efficient in nutrient removal compared to the other materials. The specific surface area values of the biochars examined is not a decisive factor for nutrient sorption. The reaction between magnesium and calcium (for the eggshell samples) ions with phosphates is responsible for the higher sorption efficiency. On the other hand, the presence of magnesium and calcium ions has a detrimental effect on the sorption of NH3-N.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Imrie, Flora E., Valentina Aina, Gigliola Lusvardi, Gianluca Malavasi, Iain R. Gibson, Giuseppina Cerrato y Basil Annaz. "Synthesis and Characterisation of Strontium and Magnesium Co-Substituted Biphasic Calcium Phosphates". Key Engineering Materials 529-530 (noviembre de 2012): 88–93. http://dx.doi.org/10.4028/www.scientific.net/kem.529-530.88.

Texto completo

Resumen

Magnesium and strontium both play important roles in the growth of bone and so are desirable ions for substitution into hydroxyapatite (HA) intended for use as bioinstructive bone substitutes. A range of compositions were prepared by a solid state method based on the nominal composition of HA (Ca10(PO4)6(OH)2), with various levels of strontium and/or magnesium substitution: strontium-substituted HA (Ca8Sr2(PO4)6(OH)2), magnesium-substituted HA (Ca9.8Mg0.2(PO4)6(OH)2 and Ca9Mg (PO4)6(OH)2), and strontium and magnesium co-substituted HA (Ca7.8Sr2Mg0.2(PO4)6(OH)2 and Ca7Sr2Mg (PO4)6(OH)2). Materials were characterised by powder X-ray diffraction, Fourier-transform infrared spectroscopy and Raman spectroscopy. These analyses indicated that the co-substituted materials were composed of mixtures of strontium-substituted hydroxyapatite and magnesium and strontium co-substituted β-tricalcium phosphate. In the magnesium-substituted materials, increased magnesium content was related to increased proportion of β-tricalcium phosphate phase, both with and without strontium co-substitution. The unsubstituted and strontium mono-substituted materials, however, were pure apatite phase, suggesting that magnesium was the destabilising factor in the phase compositions of the magnesium mono-substituted and magnesium and strontium co-substituted materials.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Machorro, J. J., J. C. Olvera, A. Larios, H. M. Hernández-Hernández, M. E. Alcantara-Garduño y G. Orozco. "Electrodialysis of Phosphates in Industrial-Grade Phosphoric Acid". ISRN Electrochemistry 2013 (19 de diciembre de 2013): 1–12. http://dx.doi.org/10.1155/2013/865727.

Texto completo

Resumen

The objective of this research was to study the purification of industrial-grade phosphoric acid (P2O5) by conventional electrodialysis. The experiments were conducted using a three-compartment cell with anion and cation membranes, and industrial acid solution was introduced into the central compartment. The elemental analysis of the diluted solution indicated that the composition of magnesium, phosphates, and sodium was reduced in the central compartment. The ratios of the concentration of the ions and the phosphates were essentially unchanged by the process. Consequently, electrodialysis could not purify the acid in the central compartment, and the migration of phosphate ions to the anolyte produced a highly concentrated phosphoric acid solution containing sulfates and chlorides as impurities. However, the migration of the phosphate ions across the membrane consumed a large amount of energy. Detailed speciation diagrams were constructed in this study. These diagrams showed that metal-phosphate complexes were predominant in the industrial phosphoric acid solution. This result explains why the ratios of the concentrations of the ion metals and the phosphates did not change in the purification process. The energy consumed in the electrodialysis indicated that the metal-phosphate complexes were less mobile than the free-phosphate ions. The speciation diagrams explained the experimental results satisfactorily.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Ding, Zhu, Bi Qin Dong y Feng Xing. "Magnesium Phosphate Cement with Large Volume of Fly Ash". Applied Mechanics and Materials 174-177 (mayo de 2012): 802–5. http://dx.doi.org/10.4028/www.scientific.net/amm.174-177.802.

Texto completo

Resumen

The accumulation of fly ash leads to severe problems in ecological environments. Various ways to excite the activity of fly ash in Portland cement based cementitious materials have been carried out for many years. In the present study, effect of large volume of fly ash in phosphate cement was studied. Dead burned magnesia, two phosphates (monoammonium phosphate and monosodium phosphate), and fly ash were used. The fabricated cement mortar specimens with different fly ash dosages were cured for 28 days in the lab air. Compressive strength was determined in 1d, 3d, 7d and 28d respectively. It is showed the compressive strength reduced with increase of fly ash content and increased with the curing time. After cured 28 days, the compressive strength of cement mortar developed to14MPa, when 80% fly ash was used. The reaction product, Na2HPO4•17H2O was found by X-ray diffraction analysis in sodium phosphate based cement. No ammonia gas was emitted and large volume of fly ash can be used in cement prepared from sodium phosphate. It is a new environmentally friendly cement material.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Radovenchyk, Yaroslav, Kateryna Hordiienko, Tamara Krysenko y Vіacheslav Radovenchyk. "Efficiency of magnesium ions removal from water in processes of its mitigation". Proceedings of the NTUU “Igor Sikorsky KPI”. Series: Chemical engineering, ecology and resource saving, n.º 4 (23 de diciembre de 2022): 88–94. http://dx.doi.org/10.20535/2617-9741.4.2022.269815.

Texto completo

Resumen

Significant concentrations of calcium and magnesium ions in natural waters force the majority of domestic drinking and energy waters to undergo preliminary softening. Therefore, mitigation technologies are becoming particularly acute today, and research in this field is increasing every year. Since water hardness is determined by the total content of calcium and magnesium ions, these elements are the focus of such research. Traditionally, it is believed that calcium ions are the first to be removed, and magnesium ions are less likely to form a solid phase. However, the effectiveness of softening technology depends equally on both cations. Therefore, sufficient attention should also be paid to magnesium ions. Sodium phosphate is considered a promising reagent in this direction. Its use in the processes of removing calcium ions allows to ensure the residual hardness of water at the level of 0.1 - 0.2 mg-eq/dm3 in a wide range of temperatures and hydrogen index. Detailed studies of the use of sodium phosphate in the processes of removing magnesium ions showed its insufficient efficiency. The effectiveness of soda-sodium softening allows to ensure at pH 11.0 - 11.5 the residual hardness of water at the level of 0.4 - 0.6 mg-eq/dm3. But the need to adjust the hydrogen index and the high consumption of reagents make this technology unsuitable for widespread use. The determining factor in water softening processes using phosphate ions is the ratio between the concentrations of phosphate ions and magnesium ions K = [PO43-, mg-eq] / [Mg2+, mg-eq]. Taking into account the strict requirements of current regulatory documents for the content of phosphates in treated waters, it is desirable to carry out the treatment with stoichiometric ratios of reagents for a more complete reaction between the components. The advantage of sodium phosphate as a reagent for removing magnesium ions can be considered the fact that in the pH range of 3.16 - 10.07 at K = 1, the residual hardness ranges from 1.8 to 3.4 mg-eq/dm3. At the same time, the minimum value of the residual stiffness was recorded at the level of 0.75 mg-eq/dm3 at pH 10.07 and K = 2. As the pH decreases, a stable decrease in efficiency is observed, although it is not very significant. Thus, during the transition from an alkaline to an acidic medium, the residual concentration of magnesium ions increases by a factor of 2, regardless of the value of the coefficient K. Similar trends persist in the case of a change in the initial hardness of water. The biggest difference is observed at values of K ≤ 1, which is explained by the deficiency of phosphate anions and the impossibility of forming a solid phase of stoichiometric composition. However, even with a stoichiometric ratio of reactants (K = 1), the residual hardness of treated water is quite significant and ranges from 2.5 to 3 mg-eq/dm3. A further increase in the dose of sodium phosphate allows to slightly reduce the residual hardness of the treated water. Thus, the minimum residual hardness of treated water at K = 2.0 is fixed at the level of 0.7 mg-eq/dm3 with an initial hardness of 22.9 mg-eq/dm3. An increase in the residual hardness of the treated water with a decrease in its initial hardness was also noted. This situation is caused, in our opinion, by a significant increase in the mass of the solid phase and an increase in pH with an increase in the dose of sodium phosphate. A significant advantage of sodium phosphate as a precipitator of calcium ions is the fact that the temperature of the water practically does not affect the efficiency of the process in a wide range of temperatures. This trend is also characteristic of magnesium ions. In the temperature range of 5 - 70 °C, the softening efficiency remains stable. Moreover, the solid phase is formed immediately after draining the solutions. If we take into account the high efficiency of phosphates in removing calcium ions, then in general, the use of phosphates for softening water can be permissible, provided that the formed solid phase is completely separated from the water. Detailed studies of the efficiency of separation of magnesium phosphate particles by settling or filtering are as important as the processes of solid phase formation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Tsintskaladze, G. P., T. M. Sharashenidze, L. G. Eprikashvili, M. G. Zautashvili, T. N. Kordzakhia y M. A. Dzagania. "Study on the structure of phosphorus-containing zeolite anionic nanoporous materials". Himia, Fizika ta Tehnologia Poverhni 13, n.º 4 (30 de diciembre de 2022): 506–12. http://dx.doi.org/10.15407/hftp13.04.506.

Texto completo

Resumen

Phosphates are specific compounds of the composition of living organisms, that play a special role in plant and animal life. The skeleton of most living organisms consists mainly of calcium, sodium, magnesium and other phosphates. Because phosphorus plays an important role in supplying nutrients to the environment, it is central to all forms of life. Therefore, interest in this type of material is great, and the scope of application is enormous, from agriculture to medicine. On the basis of clinoptilolite, a natural zeolite located in Georgia, zeolitic nanomaterials containing phosphates were obtained by two different methods. The first method is the introduction of mono-, di-, and tri-substituted sodium phosphates into the zeolite structure under conditions of boiling on a sand bath, where the introduction of phosphate ions is difficult. In the second method, phosphate ions almost completely occupy the inner structural area of the zeolite. The zeolitic nanoporous materials of mono-substituted, di-substituted and tri-substituted phosphates obtained by these methods and subsequently studied by Fourier spectroscopic method. The obtained materials have preserved the zeolitic structure, although their IR spectra are sharply different from each other, which can be explained by different anions occupying different positions in the zeolitic structure. It should be noted that after washing the obtained material with water, phosphate ions are almost completely washed out of the zeolite structure. The importance of the received materials and the perspective of their use are given.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Lu, Xiangyu, Sichen Sun, Qiqi Fan, Xiangjun Pei, Yuchao Dun, Xingguo Feng, Chen Zou y Wang Lu. "Investigation of Protective Performance of a Mg-Rich Primer Containing Aluminum Tri-Polyphosphate on AZ91D Magnesium Alloy in Simulated Acid Rain". Coatings 9, n.º 10 (9 de octubre de 2019): 649. http://dx.doi.org/10.3390/coatings9100649.

Texto completo

Resumen

Mg-rich primer (MRP) containing aluminum tri-polyphosphate functions via a galvanic mechanism to protect AZ91D alloy from corrosion in the 3 wt % NaCl solution. However, its protective performance can be strongly affected by the testing environment. Therefore, it is important to investigate the performance of the primer on magnesium alloys in an acid rain environment. In the present study, the protective performance of MRP with or without aluminum tri-polyphosphate was investigated via open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) in the simulated acid rain. Compared to the primer without aluminum tri-polyphosphate, the MRP containing aluminum tri-polyphosphate pigments exhibited better protective performance in the simulated acid rain condition. In the initial stage, the acidic condition prompted the aluminum tri-polyphosphate pigments to release phosphates and H+ to form magnesium phosphates on Mg particles, retarding their consumption rate. The Mg-rich primer with aluminum tri-polyphosphate can provide cathodic protection to AZ91D alloy for about 49 days in the simulated acid rain solution. Simultaneously, the corrosion products of Mg particles, magnesium oxides and phosphates, precipitated on the Mg particles and improved the stability of the primer. In addition, a protective film, consisting of magnesium oxides and phosphates, formed on the AZ91D substrate. Consequently, all these factors contributed to the long cathodic protection and improved corrosion resistance of MRP containing aluminum tri-polyphosphate in the simulated acid rain.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Wang, Qiang, Lili Tan, Qiang Zhang, Jianhong Qiu y Ke Yang. "PRECIPITATION CONTROL AND MECHANICAL PROPERTY OF CALCIUM PHOSPHATE–COATED AZ31B ALLOY FOR BIOMEDICAL APPLICATION". Biomedical Engineering: Applications, Basis and Communications 23, n.º 03 (junio de 2011): 193–203. http://dx.doi.org/10.4015/s1016237211002529.

Texto completo

Resumen

Surface modification is believed to be an effective way to control the biodegradation rate of magnesium alloys and improve their biological properties. In the present work, a calcium phosphate (Ca-P) coating was prepared on the AZ31B magnesium alloy by a chemical deposition method to integrate the mechanical advantages of the magnesium substrate and the good bioactivity of the ceramic coating. It was shown that the coating was mainly composed of magnesium and calcium phosphates. Scanning electron microscope coupled with the energy dispersive spectrum analyses showed that rough and crystallined Ca-P coatings with different Ca/P ratios and thickness were formed on the alloy by variation of deposition time. The corrosion resistance of AZ31B alloy was significantly improved by the Ca-P coating. Electrochemical impedance spectroscopy test was used to illustrate the reaction process of Ca-P coating on the alloy. Upon the above results, Ca-P formation mechanism on the AZ31B alloy was proposed. The heterogeneous nucleation and growth of the calcium phosphate coating may be catalyzed by the anodic dissolution of the magnesium alloy substrate in the early stage of deposition, and the deposition coating is mainly composed of the magnesium phosphate. Then calcium phosphate deposition on the alloy becomes dominant with the increase of time. Tensile test in simulated body environment results showed that the time of fracture and ultimate tensile strength for the coated AZ31B Mg alloy were higher than those of the uncoated, which is beneficial in supporting fractured bone for a longer time.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Singh, Satish S., Abhijit Roy, Boeun Lee y Prashant N. Kumta. "Aqueous deposition of calcium phosphates and silicate substituted calcium phosphates on magnesium alloys". Materials Science and Engineering: B 176, n.º 20 (diciembre de 2011): 1695–702. http://dx.doi.org/10.1016/j.mseb.2011.08.005.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Goldberg, M. A., V. V. Smirnov, M. R. Kasimova, L. I. Shvorneva, S. V. Kutsev, O. S. Antonova y S. M. Barinov. "Ceramics in the system calcium phosphates-magnesium phosphates with (Ca + Mg)/P ≈ 2". Doklady Chemistry 461, n.º 1 (marzo de 2015): 81–85. http://dx.doi.org/10.1134/s0012500815030015.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Baugé, S. M. Y., L. M. Lavkulich y H. E. Schreier. "Serpentine affected soils and the formation of magnesium phosphates (struvite)". Canadian Journal of Soil Science 93, n.º 2 (mayo de 2013): 161–72. http://dx.doi.org/10.4141/cjss2012-117.

Texto completo

Resumen

Baugé, S. M. Y., Lavkulich, L. M. and Schreier, H. E. 2013. Serpentine affected soils and the formation of magnesium phosphates (struvite). Can. J. Soil Sci. 93: 161–172. The Sumas River watershed, located in the intensive agricultural region of the Lower Fraser Valley of British Columbia (Canada), contains serpentine asbestos from a natural landslide. Serpentinic soils have a high Mg to Ca ratio that can affect soil fertility, including soil-solution P relations. The objectives of the study were: (i) to evaluate some common methods of estimating plant available phosphorus in the surface horizons of the serpentine-affected soils and those receiving large quantities of livestock manure, and (ii) to determine if there is evidence for the formation of soluble Mg phosphates, e.g., struvite, a meta-stable P phase in these soils. Seven soil nutrient extractants were used to determine major and minor elemental concentrations. Acid ammonium oxalate, 1 M HCl and Bray P1 extractions were most effective for measuring available phosphorus in these soils. Manure and fertilizer applications appear to favor the formation of Mg-phosphates, and are considered to be more soluble in terms of phosphorus than either calcium-phosphates or aluminum/iron-phosphates. X-ray diffraction, scanning electron microscopy and nuclear magnetic resonance examinations gave positive evidence for the presence of struvite in the soils.

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Мусская, Ольга Николаевна, Валентина Константиновна Крутько y Анатолий Иосифович Кулак. "SYNTHESIS OF MAGNESIUM PHOSPHATES IN A POLYMERIC MATRIX". Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, n.º 12() (15 de diciembre de 2020): 860–67. http://dx.doi.org/10.26456/pcascnn/2020.12.860.

Texto completo

Resumen

Изучена зависимость фазового состава наноразмерных фосфатов магния (MgNHPO·6HO, Mg(HPO), MgHPO·3HO, Mg(PO)•22HO) с размером кристаллитов 13-54 нм от условий осаждения из водных растворов в присутствии поливинилового спирта и его смеси с поливинилпирролидоном. В полимерной матрице дополнительно образуется примесная фаза MgOHCl. Наличие средних и двузамещенных фосфатов магния в пленках поливинилового спирта и поливинилового спирта/поливинилпирролида ингибируют их термическую деструкцию. The dependence of the phase composition of nanoscale magnesium phosphates (MgNHPO·6HO, Mg(HPO), MgHPO·3HO, Mg(PO)•22HO) with 13-54 nm crystallite size on the conditions of precipitation from aqueous solutions in the presence of the polyvinyl alcohol and its mixture with polyvinylpyrrolidone was studied. In the polymer matrix an additional impurity phase MgOHCl is formed. The presence of medium and disubstituted magnesium phosphates in polymer films of polyvinyl alcohol and polyvinyl alcohol/polyvinylpyrrolidone inhibit their thermal destruction.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Koroleva, L. F., L. P. Larionov y M. N. Dobrinskaya. "Implants and bone technology with the use of doped calcium carbonate phosphates". Diagnostics, Resource and Mechanics of materials and structures, n.º 6 (diciembre de 2020): 54–61. http://dx.doi.org/10.17804/2410-9908.2020.6.054-061.

Texto completo

Resumen

The possibility of obtaining an alloplastic biomaterial for the implant based on doped calcium carbonate-phosphates and polycaprolactone is studied. Nanocrystalline calcium carbonate-phosphate doped with cations of iron, magnesium, potassium, zinc, manganese, and silicon intended for bone repair by drug delivery is investigated. Histological studies have revealed that samples after 60 days in a living organism are covered by a connective tissue capsule. The formation of blood vessels and nerve endings is observed in the capsule.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Freund, Anke, Gerhard Eggert, Hartmut Kutzke y Bruno Barbier. "On the Occurrence of Magnesium Phosphates on Ivory". Studies in Conservation 47, n.º 3 (2002): 155. http://dx.doi.org/10.2307/1506869.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Yu, Xiaoniu, Chunxiang Qian y Xin Wang. "Biosynthesis of Magnesium Phosphates and Its Thermal Property". Science of Advanced Materials 7, n.º 9 (1 de septiembre de 2015): 1730–33. http://dx.doi.org/10.1166/sam.2015.2392.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Freund, Anke, Gerhard Eggert, Hartmut Kutzke y Bruno Barbier. "On the Occurrence of Magnesium Phosphates on Ivory". Studies in Conservation 47, n.º 3 (septiembre de 2002): 155–60. http://dx.doi.org/10.1179/sic.2002.47.3.155.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Hu, Yi-An, Pei-Chang Lee y Szu-Yuan Li. "Staghorn Renal Stone With Magnesium Ammonium Phosphates Crystals". American Journal of the Medical Sciences 359, n.º 6 (junio de 2020): 389. http://dx.doi.org/10.1016/j.amjms.2020.02.002.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Golubev, S. V., O. S. Pokrovsky y V. S. Savenko. "Homogeneous precipitation of magnesium phosphates from seawater solutions". Journal of Crystal Growth 223, n.º 4 (marzo de 2001): 550–56. http://dx.doi.org/10.1016/s0022-0248(01)00681-9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Cheng, P. T. y J. J. Grabher. "Formation and transformation of biological calcium phosphates: effects of calcium, magnesium and phosphate". Acta Crystallographica Section A Foundations of Crystallography 43, a1 (12 de agosto de 1987): C88. http://dx.doi.org/10.1107/s0108767387083119.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Ould Saleck, Ahmed, Abderrazzak Assani, Mohamed Saadi, Cyrille Mercier, Claudine Follet y Lahcen El Ammari. "Na1.85Mg1.85In1.15(PO4)3 and Ag1.69Mg1.69In1.31(PO4)3 with alluaudite-type structures". Acta Crystallographica Section E Crystallographic Communications 74, n.º 9 (24 de agosto de 2018): 1358–61. http://dx.doi.org/10.1107/s2056989018011799.

Texto completo

Resumen

Single crystals of two new phosphates, sodium magnesium indium(III) tris(orthophosphate) and silver magnesium indium(III) tris(orthophosphate), were obtained from solid-state reactions. The two phosphates are isotypic and exhibit alluaudite-type structures. They are characterized by a cationic disorder of the Mg and In sites and a partial occupation of the Na and Ag sites, respectively. The structure of both phosphates is made up of chains of edge-sharing [(Mg,In)O6] octahedra extending parallel to [10\overline{1}]. Adjacent chains are linked by PO4 tetrahedra to form a three-dimensional framework delimiting two types of channels parallel to [001] in which the monovalent cations are situated. The coordination numbers of the Na+ cations are 6 and 8, and for both Ag+ cations 6. The corresponding coordination spheres are considerably distorted.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Kerr, William J., David M. Lindsay, Vipulkumar K. Patel y Muralikrishnan Rajamanickam. "Efficient methods for enol phosphate synthesis using carbon-centred magnesium bases". Organic & Biomolecular Chemistry 13, n.º 40 (2015): 10131–35. http://dx.doi.org/10.1039/c5ob01849h.

Texto completo

Resumen

Efficient conversion of ketones into enol phosphates under mild and accessible conditions has been realised using the developed methods with di-tert-butylmagnesium and bismesitylmagnesium. Optimisation of the quench protocol resulted in high yields of enol phosphates from a range of cyclohexanones and aryl methyl ketones.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Niu, Li Yuan, Shiuan Ho Chang, Ji Xing Lin, Yi Chang Su y Guang Yu Li. "Investigation on the Compound Phosphate Film Formed in Bath with Cerium Salts on the Magnesium Aluminum Alloy". Materials Science Forum 816 (abril de 2015): 387–92. http://dx.doi.org/10.4028/www.scientific.net/msf.816.387.

Texto completo

Resumen

A composite phosphate film was formed on magnesium aluminum (Mg-Al) alloy which was impregnated in phosphating solution containing phosphate, cerium salt, organic ammonium and corrosion inhibitor. The sample was examined by scanning electron microscope (SEM), X-ray diffraction (XRD), and Energy Dispersive Spectrometer (EDS) to analyze the organization and structure of the film. Additionally, the corrosion resistance of the film of composite phosphate was also investigated by salt spray test. As a result, it shows that the components of the film formed on Mg-Al alloy contain phosphates and elemental zinc. On the other hand, the composite phosphate film possessing photo-absorption property can be used for protective layer and laser pretreatment of Mg-Al alloy.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Manzola, A. S., A. Mgaidi, M. S. Laouali y M. El Maaoui. "On precipitated calcium and magnesium phosphates during synthetic hard waters softening by monosodium phosphate". Desalination and Water Treatment 52, n.º 25-27 (11 de julio de 2013): 4734–44. http://dx.doi.org/10.1080/19443994.2013.814000.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Sinyaev, V. A., E. S. Shustikova, L. V. Levchenko, G. A. Tokseitova y D. Griggs. "Nature and Thermal Behavior of Precipitated Calcium-Magnesium Phosphates". Russian Journal of Applied Chemistry 76, n.º 9 (septiembre de 2003): 1375–78. http://dx.doi.org/10.1023/b:rjac.0000012650.94921.ee.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Golubev, S. V. "Kinetics of Calcium and Magnesium Phosphates Precipitation from Seawater". Mineralogical Magazine 62A, n.º 1 (1998): 533–34. http://dx.doi.org/10.1180/minmag.1998.62a.1.282.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Ángeles Aramendı́a, Marı́a, Vı́ctor Borau, César Jiménez, José Marı́a Marinas y Francisco José Romero. "N-alkylation of aniline with methanol over magnesium phosphates". Applied Catalysis A: General 183, n.º 1 (julio de 1999): 73–80. http://dx.doi.org/10.1016/s0926-860x(99)00042-3.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Kubarev, O. L., S. M. Barinov y V. S. Komlev. "Magnesium distribution in the synthesis of biphasic calcium phosphates". Doklady Chemistry 418, n.º 2 (febrero de 2008): 44–46. http://dx.doi.org/10.1134/s0012500808020067.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Lee, Hyoung-Sin, Tae-Wan Kim, Dong-Hyun Kim, Hong-Chae Park y Seog-Young Yoon. "Suitability evaluation of magnesium substituted biphasic calcium phosphates prepared by coprecipitation method". Journal of the Korean Crystal Growth and Crystal Technology 20, n.º 5 (31 de octubre de 2010): 237–42. http://dx.doi.org/10.6111/jkcgct.2010.20.5.237.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Yan, Ting Ting, Si Yu Wu, Qing Hua Chen, Qing Mei Liu y Jia Rong Yang. "A Novel Biodegradable Phosphate Coating on AZ31B Alloy". Applied Mechanics and Materials 707 (diciembre de 2014): 158–62. http://dx.doi.org/10.4028/www.scientific.net/amm.707.158.

Texto completo

Resumen

Mg and its alloys draw more and more attentions to be used as biodegradable medical materials. But the rapid degradation of those materials limits their clinical applications. In this article, a phosphate coating was prepared on AZ31B magnesium alloy to improve its anti-corrosion property. Morphology, composition and corrosion resistance of the coating were studied. The SEM research showed that the coating that composed of rod-like phosphates with small amount of random distributed micro-voids was approximately10-20μm in thickness. The XRD analysis indicated that the coating was mainly composed of MgO, Mg3(PO4)2and Zn3(PO4)2·xH2O. Electrochemical test showed the phosphate treatment could significant improve the corrosion resistance of AZ31B.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Devesa-Rey, Rosa, Jesús del Val, Jorge Feijoo, José P. González-Coma, Gonzalo Castiñeira y Lorena González-Gil. "Preparation of Synthetic Clays to Remove Phosphates and Ibuprofen in Water". Water 13, n.º 17 (30 de agosto de 2021): 2394. http://dx.doi.org/10.3390/w13172394.

Texto completo

Resumen

The main objective of this study consists in the synthesis of a layered double hydroxide (LDH) clay doped with magnesium and aluminum in order to test the removal of phosphates and ibuprofen in water. Two different LDH composites are assessed: oven-dried (LDHD) and calcined (LDHC). Single adsorptions of phosphate and ibuprofen showed up to 70% and 58% removal in water, when LDHC was used. A poorer performance was observed for LDHD, which presented adsorption efficiencies of 52% and 35%, respectively. The simultaneous removal of phosphate and ibuprofen in water showed that LDHC allows a greater reduction in the concentration of both compounds than LDHD. Phosphate adsorption showed a close agreement between the experimental and theoretical capacities predicted by the pseudo-second-order model, whereas ibuprofen fitted to a first-order model. In addition, phosphate adsorption showed a good fit to an intraparticle diffusion model and to Bangham model suggesting that diffusion into pores controls the adsorption process. No other mechanisms may be involved in ibuprofen adsorption, apart from intraparticle diffusion. Finally, phosphate desorption could recover up to 59% of the initial concentration, showing the feasibility of the recuperation of this compound in the LDH.

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Sinyayev, V. A., E. S. Shustikova, D. Griggs y D. V. Dorofeev. "The Nature of P-O Bonds in the Precipitated Amorphous Calcium Phosphates and Calcium Magnesium Phosphates". Glass Physics and Chemistry 31, n.º 5 (septiembre de 2005): 671–75. http://dx.doi.org/10.1007/s10720-005-0112-y.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Tsukube, T., J. D. McCully, K. R. Metz, C. U. Cook y S. Levitsky. "Amelioration of ischemic calcium overload correlates with high-energy phosphates in senescent myocardium". American Journal of Physiology-Heart and Circulatory Physiology 273, n.º 1 (1 de julio de 1997): H418—H425. http://dx.doi.org/10.1152/ajpheart.1997.273.1.h418.

Texto completo

Resumen

Previously, we have shown that potassium and magnesium (K-Mg, 20 mM each) cardioplegia ameliorated cytosolic calcium ([Ca2+]i) accumulation and was associated with enhanced functional recovery after surgically induced global ischemia in the aged heart. K-Mg cardioplegia was also shown to enhance cytosolic cytochrome oxidase I activity and mRNA levels, suggesting that enhanced functional recovery may involve the preservation of high-energy phosphates. To investigate this hypothesis, 31P nuclear magnetic resonance was used to measure serial alterations in phosphocreatine (PCr), inorganic phosphate, nucleoside triphosphate (NTP), intracellular free magnesium (Mgf), and intracellular pH (pHi) in Langendorff-perfused, aged (135 wk) rabbit hearts during preischemia, global ischemia (30 min), and reperfusion (30 min). K-Mg cardioplegia retarded PCr depletion (P <0.05) and significantly enhanced NTP preservation (P < 0.05) during ischemia and reperfusion. K-Mg cardioplegia also attenuated the increase in Mgf during ischemia (P < 0.05). These results were correlated with amelioration of [Ca2+]i accumulation during ischemia and preservation of left ventricular function after reperfusion and suggest that optimal functional recovery from surgically induced ischemia is provided by K-Mg cardioplegia in the aged myocardium.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Magnesium phosphates"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros