Variogram Roughness Method for Casting Surface Characterization

Author(s):  
Daniel Wilhelm Schimpf ◽  
Frank Earl Peters
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.


2019 ◽  
Vol 782 ◽  
pp. 1114-1120 ◽  
Author(s):  
Chi-Ming Wu ◽  
Yi-Jung Lu ◽  
Shyuan-Yow Chen ◽  
Shih-Cheng Wen ◽  
Chia-Hung Wu ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 295 ◽  
Author(s):  
Sébastien Champagne ◽  
Ehsan Mostaed ◽  
Fariba Safizadeh ◽  
Edward Ghali ◽  
Maurizio Vedani ◽  
...  

Absorbable metals have potential for making in-demand rigid temporary stents for the treatment of urinary tract obstruction, where polymers have reached their limits. In this work, in vitro degradation behavior of absorbable zinc alloys in artificial urine was studied using electrochemical methods and advanced surface characterization techniques with a comparison to a magnesium alloy. The results showed that pure zinc and its alloys (Zn–0.5Mg, Zn–1Mg, Zn–0.5Al) exhibited slower corrosion than pure magnesium and an Mg–2Zn–1Mn alloy. The corrosion layer was composed mostly of hydroxide, carbonate, and phosphate, without calcium content for the zinc group. Among all tested metals, the Zn–0.5Al alloy exhibited a uniform corrosion layer with low affinity with the ions in artificial urine.


Langmuir ◽  
2008 ◽  
Vol 24 (17) ◽  
pp. 9500-9507 ◽  
Author(s):  
Claudia Kolbeck ◽  
Manuela Killian ◽  
Florian Maier ◽  
Natalia Paape ◽  
Peter Wasserscheid ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1929
Author(s):  
Alexander Rodríguez ◽  
Francisco Burgos-Flórez ◽  
José D. Posada ◽  
Eliana Cervera ◽  
Valtencir Zucolotto ◽  
...  

Neuronal damage secondary to traumatic brain injury (TBI) is a rapidly evolving condition, which requires therapeutic decisions based on the timely identification of clinical deterioration. Changes in S100B biomarker levels are associated with TBI severity and patient outcome. The S100B quantification is often difficult since standard immunoassays are time-consuming, costly, and require extensive expertise. A zero-length cross-linking approach on a cysteamine self-assembled monolayer (SAM) was performed to immobilize anti-S100B monoclonal antibodies onto both planar (AuEs) and interdigitated (AuIDEs) gold electrodes via carbonyl-bond. Surface characterization was performed by atomic force microscopy (AFM) and specular-reflectance FTIR for each functionalization step. Biosensor response was studied using the change in charge-transfer resistance (Rct) from electrochemical impedance spectroscopy (EIS) in potassium ferrocyanide, with [S100B] ranging 10–1000 pg/mL. A single-frequency analysis for capacitances was also performed in AuIDEs. Full factorial designs were applied to assess biosensor sensitivity, specificity, and limit-of-detection (LOD). Higher Rct values were found with increased S100B concentration in both platforms. LODs were 18 pg/mL(AuES) and 6 pg/mL(AuIDEs). AuIDEs provide a simpler manufacturing protocol, with reduced fabrication time and possibly costs, simpler electrochemical response analysis, and could be used for single-frequency analysis for monitoring capacitance changes related to S100B levels.


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