scholarly journals Mechanical, Electrical, and Biological Properties of Mechanochemically Processed Hydroxyapatite Ceramics

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2216
Author(s):  
Sujata Swain ◽  
Rakesh Bhaskar ◽  
Mukesh Kumar Gupta ◽  
Sonia Sharma ◽  
Sudip Dasgupta ◽  
...  

The effect of the sintering temperature on densification and the resultant mechanical, electrical, and biological properties of mechanochemically processed hydroxyapatite (HAp) samples was investigated. HAp samples were sintered at 1200, 1250, and 1300 °C for 4 h, respectively. HAp samples sintered at 1250 °C showed better mechanical properties, which was attributed to their smaller grain size compared to HAp samples at higher sintering temperatures. The nearly identical value of the dielectric constant (εr) and better cell proliferation was exhibited by HAp samples sintered at 1250 and 1300 °C, respectively. At ~210 °C, in all the samples sintered at different temperatures, a dielectric anomaly was obtained, which was attributed to the phase transition temperature of the HAp system. Dielectric properties near the phase transition temperature showed a dielectric relaxation-type of behavior, which was attributed to the re-orientational motion of OH− ions in the HAp system. Higher cell proliferation and viability were exhibited by the HAp1300 samples, whereas comparatively equivalent cell growth and higher mechanical strength were observed in the HAp1250 samples.

Author(s):  
Uwe Lücken ◽  
Joachim Jäger

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.


RSC Advances ◽  
2021 ◽  
Vol 11 (41) ◽  
pp. 25664-25676
Author(s):  
Abir Hadded ◽  
Jalel Massoudi ◽  
Sirine Gharbi ◽  
Essebti Dhahri ◽  
A. Tozri ◽  
...  

The present work reports a detailed study of the spin dynamics, magnetocaloric effect and critical behaviour near the magnetic phase transition temperature, of a ferrimagnetic spinel Cu1.5Mn1.5O4.


2017 ◽  
Vol 1 (6) ◽  
Author(s):  
S. Cervera ◽  
M. Trassinelli ◽  
M. Marangolo ◽  
C. Carrétéro ◽  
V. Garcia ◽  
...  

2021 ◽  
Vol 291 ◽  
pp. 129519
Author(s):  
Yuwaraj K. Kshetri ◽  
Bina Chaudhary ◽  
Takashi Kamiyama ◽  
Tae-Ho Kim ◽  
Federico Rosei ◽  
...  

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