scholarly journals PRECIPITATION OF CALCIUM PHOSPHATES FROM A MODEL BLOOD PLASMA SOLUTION ON STEEL GRADE 12X18N10T

Author(s):  
Татьяна Ивановна Правильникова ◽  
Ольга Александровна Голованова

В работе представлено исследование процессов осаждения минеральноорганических образований в модельном растворе плазмы крови в присутствии добавок альбумина, глицина, глюкозы, глутаминовой и молочной кислот. Методом рентгенофлуоресцентного анализа изучен фазовый состав образцов. Для измерения площади покрытия образца модифицированным фосфатом кальция были сделаны фотографии. На фотографиях были выделены области покрытия твердой фазой и с помощью программы ToupView произведен расчет степени покрытия образцов стали. Осаждение кристаллической фазы происходит на всех исследуемых образцах. Отличия заключаются в распределении кристаллов по поверхности пластины. Добавка альбумин ингибирует процесс осаждения гидроксилапатита на исследуемых образцах. Показано, что добавки глюкозы, глутаминовой и молочной кислот катализируют процесс осаждения гидроксилапатита на поверхности стального образца. В процентном соотношении, от общей площади фотографии, наибольшее количество осажденного порошка гидроксилапатита наблюдается у образцов с добавлением глюкозы. The paper presents a study of the processes of precipitation of mineral-organic formations in a model solution of blood plasma in the presence of additives of albumin, glycine, glucose, glutamic and lactic acids. The phase composition of the samples was studied by the X-ray diffraction analysis. Photos were taken to measure the surface area of the sample with modified calcium phosphate. The solid phase coating areas were highlighted in the photos and the degree of coating of steel samples was calculated using the ToupView software. The deposition of the crystal phase occurs on all the studied samples. The differences are in the distribution of crystals on the surface of the plate. The additive albumin inhibits the deposition of hydroxyapatite on the studied samples. It is shown, that additions of glucose, glutamic and lactic acids catalyze the process of hydroxylapatite deposition on the surface of a steel sample. As a percentage of the total area of the image, the largest amount of precipitated hydroxylapatite powder is observed in samples with the addition of glucose.

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.


Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3999-4004
Author(s):  
HIROSHI MATSUI ◽  
KAZUFUMI WATANABE

Antimony-platinum bilayers were prepared on titanium substrates by the two-step electrodeposition in the usual baths, and then surface alloys were formed by the atom diffusion in the solid phase. The simple antimony layer was little influenced by the substrate in both the measurements of X-ray diffraction and the i - E characteristic in a sulfuric acid solution. Regarding the bilayers, the catalytic activity in hydrogen evolution reaction was very sensitive to the presence of platinum, while the hydrogen adsorbability was quite insensitive. An interaction between antimony and platinum was confirmed by the appearance of a new dissolution wave in the electrochemical measurement and the occurrence of a new diffraction in the X-ray diffraction pattern after the heat-treatment of about 400°C. Although the new diffraction disagreed with any of the reported alloys, clear diffraction pattern of PtSb 2 alloy was observed, when the bilayers were heat-treated at about 600°C for one hour. Considering the penetration depth of X-ray, the alloying of antimony and platinum seems to occur also at low temperatures at least at the top surface.


2014 ◽  
Vol 215 ◽  
pp. 470-473 ◽  
Author(s):  
Tamara V. Drokina ◽  
German A. Petrakovskii ◽  
Dmitrii A. Velikanov ◽  
Maksim S. Molokeev

In this paper we are reported about a peculiarity of the crystal structure and the magnetic state of TmFeTi2O7. The compound TmFeTi2O7 has been synthesizedusing the solid-phase reaction method. Using X-ray diffraction method the disorder in the distribution of the iron ions over five nonequivalent crystal sites was observed, also the populations of the iron atoms positions were determined. We show that below Tf = 6 K the magnetization of TmFeTi2O7 depends on the magnetic history of the sample. There are indications for spin glass state. This results allow us to assume the state of spin glass is realized below freezing temperature Tf = 6 K in TmFeTi2O7.


2017 ◽  
Vol 64 (3-4) ◽  
pp. 155-162
Author(s):  
Aleksandra Gorączko ◽  
Andrzej Olchawa

AbstractThe paper presents results of a study on the amount of water associated with the solid phase of the clay water system at the plastic limit. Two model monomineral clays, namely kaolinite, and montmorillonite, were used in the study. The latter was obtained by gravitational sedimentation of Na-bentonite (Wyoming).The calculated mean number of water molecule layers on the external surface of montmorillonite was 14.4, and water in interlayer spaces constituted 0.3 of the water mass at the plastic limit.The number of water layers on the external surface of kaolinite particles was 63, which was related to the higher density of the surface electrical charge of kaolinite compared to that of montmorillonite.The calculations were made on the basis of the external surface area of clays and the basal spacing at the plastic limit measured by an X-ray diffraction test. The external surface area of clays was estimated by measuring sorption at a relative humidity p/p0 = 0.5.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


2013 ◽  
Vol 750-752 ◽  
pp. 506-511
Author(s):  
Yuan Yuan Li ◽  
Gui Xia Dong ◽  
Bi Yan Zhu ◽  
Qiu Xiang Liu ◽  
Di Wu

As a research object, the samples with various Ba/Ti ratios (Ba/Ti=0.95~1.05) were synthesized by solid phase reaction method. Effect of sintering temperatures and Ba/Ti ratio on dielectric properties and crystal structure of BaTiO3ceramic were investigated. Crystal structure and crystal phase composition were investigated by scanning electron microscopy and X-ray diffraction. The dielectric properties were studied by Agilent 4294A at 1 kHz. The results show that the BaTiO3ceramic has high permittivity and dielectric loss at 1340°C. The permittivity of BaTiO3ceramic with Ba/Ti=0.95 change small as the sintering temperatures vary at 1320°C. With the increasing of Ba/Ti ratio, the Curie temperature first increases and then decreases as the sample sintering at 1320°C. When Ba/Ti=1, the Curie temperature increase with the sintering temperature increasing.


2021 ◽  
Vol 103 (3) ◽  
pp. 67-73
Author(s):  
A.A. Toibek ◽  
◽  
K.T. Rustembekov ◽  
D.A. Kaikenov ◽  
M. Stoev ◽  
...  

For the first time, double gadolinium tellurites of the composition GdMIITeO4.5 (MII — Sr, Ba) were synthesized by the solid-phase method. The solid-phase synthesis of samples was carried out from decrepitated gadolinium (III) and tellurium (IV) oxides, strontium, and barium carbonates according to the standard ceramic technology. The synthesis was carried out in the temperature range of 800-1100 °C. The samples obtained were confirmed by X-ray phase analysis. X-ray phase analysis was carried out on an Empyrean instrument in the XRDML Pananalitical format. The intensity of the diffraction maxima was estimated on a 100-point scale. X-ray diffraction patterns indexing of the powder of gadolinium tellurites — alkaline earth metals studied were carried out by the homology method. The reliability and correctness of the results of indexing the X-ray diffraction patterns are confirmed by the good agreement between the experimental and calculated values of the interplanar distances (d) and the agreement between the values of the X-ray and pycnometric densities. It was found that compounds GdSrTeO4.5 and GdBaTeO4.5 crystallize in the monoclinic system and have the unit cell parameters, namely GdSrTeO4.5 — a = 12.7610, b = 10.4289, c = 8.6235 Å, V° = 1141.83 Å3, β = 95.77°, Z = 5, ρrent. = 3.22, ρpikn. = (3.10±0.09) g/cm3; GdBaTeO4.5 — a = 15.7272, b = 15.8351, c = 7.1393 Å, V° = 1769.72 Å3, β = 95.53°, Z = 8, ρrent = 3.71, ρpick = (3.61±0.10) g/cm3. Using the Landiya method, the standard heat capacities of the compounds were estimated from the calculated values of the standard entropies, and the temperature dependences of the heat capacities of the gadolinium tellurites synthesized were determined in the temperature range of 298–850 K.


2018 ◽  
Vol 790 ◽  
pp. 9-14
Author(s):  
Shin Ichi Furusawa ◽  
Yohei Minami

MAlSi3O8 (M = Li, Na, K) was synthesized by solid-phase reaction at 1000 °C using M2CO3 (M = Li, Na, K), Al2O3, and SiO2 as the starting materials, and its ionic conduction was studied in the temperature range 475–800 K. It was confirmed from powder X-ray diffraction profiles that the crystalline phases of the prepared MAlSi3O8 were the same as those of orthoclase. Moreover, the ionic conductivity of NaAlSi3O8 was about 10 times higher than that of LiAlSi3O8 and KAlSi3O8. The activation energies for ionic conduction were estimated to be in the range of 0.70–0.77 eV, with NaAlSi3O8 exhibiting the lowest activation energy. The result suggests that the magnitude of the activation energy cannot be determined only from the ionic radius.


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