scholarly journals Compositional, structural, and surface characterization of heat-treated halloysite samples: Influence of surface treatment on photochemical activity

2021 ◽  
Vol 212 ◽  
pp. 106222
Author(s):  
Balázs Zsirka ◽  
Veronika Vágvölgyi ◽  
Katalin Győrfi ◽  
Erzsébet Horváth ◽  
Róbert K. Szilágyi ◽  
...  
2012 ◽  
Vol 258 (10) ◽  
pp. 4377-4382 ◽  
Author(s):  
Sang-Hyun An ◽  
Takuya Matsumoto ◽  
Hiroyuki Miyajima ◽  
Jun-Ichi Sasaki ◽  
Ramaswamy Narayanan ◽  
...  

2011 ◽  
Vol 158 (6) ◽  
pp. C178 ◽  
Author(s):  
Anawati ◽  
Spyros Diplas ◽  
Bo̸rge Holme ◽  
Jan Ketil Solberg ◽  
Ragnvald H. Mathiesen ◽  
...  

2018 ◽  
Vol 17 ◽  
pp. 1-9
Author(s):  
Luiz Carlos do Carmo Filho ◽  
Ana Paula Pinto Martins ◽  
Amália Machado Bielemann ◽  
Anna Paula da Rosa Possebon ◽  
Fernanda Faot

Aim: This study characterized the implant surfaces available on the Brazilian market in terms of topography, chemical composition, and roughness. Methods: The following brands were selected according to their surfaces: Kopp (Ko), Signo Vinces (Sv), Neodent (Ne), Osseotite (Os) NanoTite (Nt), SIN (Si), Titanium Fix (Tf), conventional Straumann (Str), Active SLA (SLA). The morphological analysis and the alloy impurities and implant surface contaminants were analyzed by SEM-EDS. Surface roughness parameters and 3-D reconstructions were obtained by laser microscopy (20x). Two distinct areas were evaluated: i) the cervical portion (no surface treatment), and ii) the middle third (treated surface). Results: The characterization of the implant surfaces by SEM showed morphological differences between the thread geometries and surface morphology at 800x and 2000x magnification. The EDS elemental analysis showed a predominance of titanium (Ti) for all implants. The SLA surface showed only peaks of Ti while other implants brands showed traces of impurities and contaminants including Al, C, PR, F, Mg, Na, Ni, O, P, and SR. The implant surface roughness in the cervical portion did not exceed Ra 0.5–1.0 μm, constituting a minimally rough surface and obtaining acceptable standards for this region. Only Nt, Str, and SLA presented Ra above 2 μm in the middle third area showing a rough surface favorable for osseointegration. Conclusion: This study concluded that there is no established standard for morphology, chemical composition and implant surface roughness that allows a safe comparison between the available dental implant surfaces. National implant brands generally contain more impurities and surface contaminants than their international counterparts and were consequently more sensitive to the surface treatment techniques.


2005 ◽  
Vol 285 (2) ◽  
pp. 653-664 ◽  
Author(s):  
Aaron P. Malloy ◽  
Gregory J. Browning ◽  
Scott W. Donne

Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).


Author(s):  
Shozo Ikeda ◽  
Hirotoshi Hayakawa ◽  
Daniel R. Dietderich

Pb addition makes easier to form the high Tc phase in the BSCCO system. However, Pb easily vaporized at high temperature. A controlled Pb potential method has been applied to grow the high Tc phase in films. Initially, films are deposited on cleaved MgO substrates using an rf magnetron sputtering system. These amorphous as-deposited films are heat treated in a sealed gold capsule along with a large pellet of Pb-added BSCCO. Details of the process and characterization of the films have been reported elsewhere (1). Films trated for 0.5h at 850° C contain mainly the low Tc phase with a small amount of the high Tc phase. Hawever, films treated for 3h at 850°C consist mainly of the high Tc phase. This film is superconductive with a Tc(zero) of 106K. The Pb/Bi ratio of the films, analysed by SEM- EDS, are 0.12 and 0.18 for heat tratment times of 0.5 and 3h, respectively. The present study investigates the modulated structures of these films using HREM.


Alloy Digest ◽  
1968 ◽  
Vol 17 (12) ◽  

Abstract Brush Alloy 190 is a mill-heat treated beryllium copper strip with a tensile strength up to 190,000 psi. It eliminates the need of customer heat-treating by providing high properties combined with exceptional formability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: Cu-194. Producer or source: Brush Beryllium Company.


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