The characterization of the micro-structure of cobalt on γ-Al2O3 for FTS

Keyword(s):  
2016 ◽  
Vol 3 ◽  
pp. 47-50
Author(s):  
Birgit Neitzel ◽  
Florian Aschermayer ◽  
Milan Kracalik ◽  
Sabine Hild

Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC) were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.


2020 ◽  
Vol 10 (21) ◽  
pp. 7520
Author(s):  
Maria Menini ◽  
Francesco Pera ◽  
Francesco Bagnasco ◽  
Francesca Delucchi ◽  
Elisa Morganti ◽  
...  

Background: The aim of this study was to evaluate the macro- and micro-structure and the chemical composition of the surface of 5 different commercially available dental implants. Roughness values were also calculated. Materials and Methods: 1 zirconia implant (NobelPearl of Nobel Biocare) and 4 titanium implants, Syra (Sweden&Martina), Prama (Sweden&Martina), T3 (Biomet 3i), and Shard (Mech&Human), were analyzed through SEM-EDX analysis and quantitative evaluation of surface roughness (1 sample), and XPS chemical analysis (1 sample). Surface roughness was quantitatively assessed using the stereo-SEM method (SSEM). The following area roughness parameters were calculated, according to ISO25178: Sa, Sz, and Sdr. Results: From the SEM observations, all the implants analyzed presented modern well-developed micro-structures as the result of the specific process of double acid etching alone or combined with other additional treatments. Roughness values were generally greater at the level of the implant body and lower at the collar. The chemical characterization of the implant surfaces exhibited excellent results for all of the implants and indicated good care in the production processes. Conclusions: All the samples were well-conceived in terms of topography and surface roughness, and clean in terms of chemical residues.


2019 ◽  
Vol 29 (3) ◽  
pp. 1787-1800 ◽  
Author(s):  
Yihuai Zhang ◽  
Maxim Lebedev ◽  
Gregory Smith ◽  
Yu Jing ◽  
Andreas Busch ◽  
...  

ABSTRACT Characterization of coal micro-structure and the associated rock mechanical properties are of key importance for coal seam exploration, coal bed methane development, enhanced coal bed methane production and CO2 storage in deep coal seams. Considerable knowledge exists about coal chemical properties, but less is known about the nanoscale to the micro-scale structure of coals and how they change with coal strength across coal ranks. Thus, in this study, 3D X-ray micro-computed tomography (with a voxel size of 3.43 µm) and nano-indentation tests were conducted on coal samples of different ranks from peat to anthracite. The micro-structure of peats showed a well-developed pore system with meso- and micro-pores. The meso-pores essentially disappear with increasing rank, whereas the micro-pores persist and then increase past the bituminous rank. The micro-fracture system develops past the peat stage and by sub-bituminous ranks and changes into larger and mature fracture systems at higher ranks. The nano-indentation modulus showed the increasing trend from low- to high-rank coal with a perfect linear relationship with vitrinite reflectance and is highly correlated with carbon content as expected.


Author(s):  
Cecep Suganda ◽  
Edi Sutoyo ◽  
Dwi Yuliaji

<p>Bicycle stem is the link between handlebar (handlebar) with steerer tube (fork). Stem one of the bike parts to<br />note and Each type of bike is different for the size and specifications stemnya. This research aims to. Obtained<br />characterization of alumunium casting material as a material for making stem bikes with casting temperature of<br />700 ° C, and temperature variations of room temperature (30 ° C), 100 ° C, 150 ° C, 200 ° C, and characteristic<br />hardness values stem between piston waste material and stem. The piston waste is melted at the melting<br />furnace at a temperature of 700 ° C. then cast into the mold. After obtaining the specimen and then testing the<br />material characteristics include chemical composition, microstructure, and hardness. The result of the research<br />after casting with variation of the molded temperture has different material characteristic values, ie: chemical<br />composition which has no change before and after casting, the microt structure has little porous defect, and the<br />hardness value where the higher the mold temperature the lower the hardness . Conclusions of data processing<br />The highest value of piston recycled hardness is 93 HV when compared to the hardness of 61.2 HV stem bike<br />material, the hardness is more than enough and from the composition test there is a difference of Si 12%<br />composition. Result of micro structure at foundry with 4 variation still have defect of cast (porous and<br />shrinkage). the stam bike hardness test has an average hardness value of 64.2 HV whereas for the hardness<br />value of piston waste casting results show the hardness value of 91 HV with mold temperature 30 ° C, 93 HV<br />with mold temperture 100 ° C, 89 HV with mold temperature 150 ° C, 87 HV with mold temperature 200 ° C. The<br />higher the mold temperature, the lower the hardness of the material.</p>


2020 ◽  
Vol 10 (17) ◽  
pp. 6110
Author(s):  
Chuan Jin ◽  
Yu He ◽  
Yan Tang ◽  
Zhongye Xie ◽  
Lixin Zhao ◽  
...  

We present an effective method for the topography characterization of large gradient micro-structure based on digital holographic microscope (DHM). Due to the limitation of numerical aperture of DHM system, high frequency information corresponding to large gradient regions of specimen is prohibited from entering the imaging system and the complete collection of specimen features cannot be implemented. To solve this problem, we use a common configuration of off-axis DHM system to capture the holograms from multiple angles of the sample, and the various object waves coming from the sample of different tilt angle is corrected and spliced into a fully topography by multi-angle stitching process. In this way, the measurement of large gradient topography of specimen can be realized. Experimental results of large gradient microlens demonstrate the practicability and precision of the presented method.


2017 ◽  
Vol 17 (9) ◽  
pp. 6859-6866 ◽  
Author(s):  
Chunhua Guo ◽  
Xiang Wu ◽  
Zhang Chengwei ◽  
Wangang Chen ◽  
Hao Zhang

2006 ◽  
Vol 05 (02n03) ◽  
pp. 279-284
Author(s):  
HUI-LING ZHAO ◽  
BING LIU ◽  
XING-TANG ZHANG ◽  
YUN-CAI LI ◽  
YA-BIN HUANG ◽  
...  

Lithium titanate powders of different morphologies were synthesized by improved hydrothermal technique, which was performed at 90°C and atmospheric pressure for 20 h. By changing the solution in the reaction, nanoparticles, flowers petal-like structures, and nanorods of lithium titanate have been obtained, especially nanoparticles with well-crystalline structures were obtained. The morphology and micro-structure of the as-synthesized products were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and selected-area electron diffraction (SAED).


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