Titania versus Ceria Alumina/Zirconia Composites: Structural Aspects and Biological Tolerance

2012 ◽  
Vol 529-530 ◽  
pp. 595-600
Author(s):  
Simona Cavalu ◽  
Viorica Simon ◽  
Cristian Ratiu ◽  
Vasile Rus ◽  
Ipek Akin ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Histological Evaluation ◽  
X Ray Diffraction ◽  
In Vivo Evaluation ◽  
X Ray ◽  
Fluoride Treatment ◽  
Qualitative And Quantitative ◽  
Quantitative Results ◽  
Structural Aspects

The aim of our study is to compare the structural and biological tolerance of novel Al2O3/3Y-TZP composites with ceria respectively titania addition (5 wt%). Scanning electron microscopy, X-ray diffraction, infrared spectroscopy and XPS results are reported for structural characteristics and surface modifications upon different fluoride treatments. The biocompatibility of the samples was evaluated using an animal model (rabbit). The explants were analyzed at a specific period (6 weeks).The sections of implanted bone area were subjected to histological evaluation. Upon correlating the structural properties and in vivo evaluation, we concluded that the addition of both TiO2and CeO2to Al2O3/3Y-TZP implies similar properties and satisfactory biological tolerance. With respect to the surface treatment, qualitative and quantitative results show that the alumina/zirconia with titania addition are more sensitive to fluoride treatment.

XRD Analysis of Ferrite Ceramics with Different Heat Treatment

2019 ◽  
Vol 970 ◽  
pp. 314-319
Author(s):  
Anatoly P. Surzhikov ◽  
Sergei A. Ghyngazov ◽  
Vitaly A. Vlasov ◽  
Oldrich Stary ◽  
Alexey N. Sokolovskiy
Keyword(s):  
Heat Treatment ◽  
Rietveld Method ◽  
Structural Characteristics ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Qualitative And Quantitative ◽  
Diffraction Patterns

A comparative analysis of the structural characteristics of LiZnTi ferrites sintered at the temperature of 1280 and 1360 K was performed. The qualitative and quantitative X-ray diffraction (XRD) analysis of the samples, main phase structural analysis, and unit cell parameters were carried out using the non-standard method (Rietveld method). Diffraction patterns were recorded on an ARL X'TRA diffractometer in the CuKα1+α2 and CuKβ scanning modes.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

scholarly journals Mechanochemical Preparation of Slow Release Fertilizer Based on Glauconite–Urea Complexes

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507 ◽  
Author(s):  
Maxim Rudmin ◽  
Elshan Abdullayev ◽  
Alexey Ruban ◽  
Ales Buyakov ◽  
Bulat Soktoev
Keyword(s):  
Milling Time ◽  
Slow Release ◽  
Mechanochemical Activation ◽  
Structural Characteristics ◽  
Fluorescence Analysis ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Slow Release Fertilizers

We investigated the mechanochemical synthesis of complex slow release fertilizers (SRF) derived from glauconite. We studied the effectiveness of the mechanical intercalation of urea into glauconite using planetary and ring mills. The potassium-nitric complex SRFs were synthesized via a mechanochemical method mixing glauconite with urea in a 3:1 ratio. The obtained composites were analyzed using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence analysis, and infrared spectroscopy. The results show that as duration of mechanochemical activation increases, the mineralogical, chemical, and structural characteristics of composites change. Essential modifications associated with a decrease in absorbed urea and the formation of microcrystallites were observed when the planetary milling time increased from 5 to 10 min and the ring milling from 15 to 30 min. Complete intercalation of urea into glauconite was achieved by 20 min grinding in a planetary mill or 60 min in a ring mill. Urea intercalation in glauconite occurs much faster when using a planetary mill compared to a ring mill.

Nanostructured TiO2-Based Composites for Light Absorption

2014 ◽  
Vol 975 ◽  
pp. 207-212
Author(s):  
Dayse I. dos Santos ◽  
Olayr Modesto Jr. ◽  
Luis Vicente A. Scalvi ◽  
Americo S. Tabata
Keyword(s):  
Metal Oxide ◽  
Light Absorption ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Oxide Powders

Metal oxide nanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first process produces directly a two-phase material, while the sol-gel powder never showed second phase below 600°C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.

The high-pressure cadmium borate Cd6B22O39·H2O

2015 ◽  
Vol 70 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Gerhard Sohr ◽  
Nina Ciaghi ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Cell Dimensions ◽  
Temperature Experiment ◽  
Unit Cell Dimensions ◽  
Ir And Raman

AbstractSingle crystals of the hydrous cadmium borate Cd6B22O39·H2O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 °C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B2O3 were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd6B22O39·H2O is similar to that of the type M6B22O39·H2O (M=Fe, Co). Layers of corner-sharing BO4 groups are interconnected by BO3 groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [R1=0.0379, wR2=0.0552 (all data)] with the unit cell dimensions a=1837.79(5), b=777.92(2), c=819.08(3) pm, and V=1171.00(6) Å3. The IR and Raman spectra reflect the structural characteristics of Cd6B22O39·H2O.

scholarly journals Optimized Chitosan/Anion Polyelectrolyte Complex Based Inserts for Vaginal Delivery of Fluconazole: In Vitro/In Vivo Evaluation

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 227 ◽  
Author(s):  
Bayan Darwesh ◽  
Hibah Aldawsari ◽  
Shaimaa Badr-Eldin
Keyword(s):  
Vaginal Delivery ◽  
Polyelectrolyte Complex ◽  
Inflammatory Cells ◽  
Antifungal Drugs ◽  
Vaginal Candidiasis ◽  
Histological Evaluation ◽  
Anionic Polymer ◽  
In Vivo Evaluation

(1) Background: Fluconazole, used orally for vaginal candidiasis, has reported gastrointestinal side effects. Therefore, researchers directed towards the drug vaginal delivery. However, vaginal delivery is limited by poor retention and leakage. Thus, this work aimed at exploring chitosan/anion polyelectrolyte complex (PEC) for the formulation of fluconazole vaginal inserts with controlled release and appreciable mucoadhesion. (2) Methods: PECs were prepared and assessed for interactions. Fluconazole PEC based vaginal inserts were prepared by lyophilization using mannitol. 3151 factorial design was applied to investigate the effect of the anion type and Chitosan/anion ratio on the inserts mucoadhesion and release properties. The optimized insert [based on 5:5 chitosan: anionic polymer (sodium alginate)] release was modulated by the release retardant; Compritol® 888. The selected formulation was subjected to microbiological and histological evaluation. (3) Results: Fluconazole inserts showed satisfactory drug content, acceptable friability percentages and highest swelling indices at six hours. Statistical analysis showed significant effect of the studied factors on detachment force and release properties. Microbiological assays revealed significantly higher antifungal activity of inserts compared to fluconazole solution. Reduced inflammatory cells were confirmed by histological evaluation. (4) Conclusion: CH/Alg based vaginal insert could be a promising platform for vaginal delivery of antifungal drugs used for vaginal candidiasis treatment.

Effects of dietary alteration of bicarbonate and magnesium on rat bone

1986 ◽  
Vol 250 (2) ◽  
pp. F302-F307 ◽  
Author(s):  
J. M. Burnell ◽  
C. Liu ◽  
A. G. Miller ◽  
E. Teubner
Keyword(s):  
Crystal Structure ◽  
Bone Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growing Rats ◽  
Final Composition ◽  
Rat Bone

To study the effects of bicarbonate and magnesium on bone, mild acidosis and/or hypermagnesemia were produced in growing rats by feeding ammonium chloride and/or magnesium sulfate. Bone composition, quantitative histomorphometry, and mineral x-ray diffraction (XRD) characteristics were measured after 6 wk of treatment. The results demonstrated that both acidosis (decreased HCO3) and hypermagnesemia inhibited periosteal bone formation, and, when combined, results were summative; and the previously observed in vitro role of HCO3- and Mg2+ as inhibitors of crystal growth were confirmed in vivo. XRD measurements demonstrated that decreased plasma HCO3 resulted in larger crystals and increased Mg resulted in smaller crystals. However, the combined XRD effects of acidosis and hypermagnesemia resembled acidosis alone. It is postulated that the final composition and crystal structure of bone are strongly influenced by HCO3- and Mg2+, and the effects are mediated by the combined influence on both osteoblastic bone formation and the growth of hydroxyapatite.

scholarly journals Influence of the growth parameters of TiO2 thin films deposited by the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Deposition Parameters

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.

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