Assessment of atomic force and scanning electron microscopes for characterization of commercial and electrospun nylon membranes for coke removal from wastewater

2013 ◽  
Vol 52 (34-36) ◽  
pp. 6611-6619 ◽  
Author(s):  
Elham Mirtalebi ◽  
Mohammad Mahdi A. Shirazi ◽  
Ali Kargari ◽  
Meisam Tabatabaei ◽  
Seeram Ramakrishna
2017 ◽  
Vol 902 ◽  
pp. 012017 ◽  
Author(s):  
Ashish Suri ◽  
Andrew Pratt ◽  
Steve Tear ◽  
Christopher Walker ◽  
Mohamed El-Gomati

2010 ◽  
Vol 645-648 ◽  
pp. 779-782 ◽  
Author(s):  
Hidenori Koketsu ◽  
Tomoaki Hatayama ◽  
K. Amijima ◽  
Hiroshi Yano ◽  
Takashi Fuyuki

.   Crystallographically specific pyramidal planes in 4H-SiC could be naturally formed at mesa sidewalls by a thermal etching at 900oC in a chlorine (Cl2) based ambience. The mesa structures have been fabricated on the 4H-SiC C-face with 0-45o off-angle toward [11-20]. The etched surface was rather smooth, and bunched step structures on the specific pyramidal planes were not observed with atomic force and scanning electron microscopes. The formation mechanisms of the specific pyramidal planes at mesa sidewalls are discussed on the basis of these experimental results.


2008 ◽  
Vol 16 (2) ◽  
pp. 18-21
Author(s):  
H. Hariharan ◽  
A. Koschan ◽  
B. Abidi ◽  
D. Page ◽  
M. Abidi ◽  
...  

When imaging a sample, it is desirable to have the entire area of interest in focus in the acquired image. Typically, microscopes have a limited depth of field (DOF) and this makes the acquisition of such an all-in-focus image difficult. This is a major problem in many microscopic applications and applies equally in the realm of scanning electron microscopy as well. In multifocus fusion, the central idea is to acquire focal information from multiple images at different focal planes and fuse them into one all-in-focus image where all the focal planes appear to be in focus.Large chamber scanning electron microscopes (LC-SEM) are one of the latest members in the SEM family that has found extensive use for nondestructive evaluations. Large objects (~1 meter) can be scanned in micro- or nano-scale using this microscope. An LC-SEM can provide characterization of conductive and non-conductive surfaces with a magnification from 10× to 200,000×. The LC-SEM, as with other SEMs, suffers from the problem of limited DOF making it difficult to inspect a large object while keeping all areas in focus.


2014 ◽  
Vol 407 (11) ◽  
pp. 3045-3053 ◽  
Author(s):  
Vanessa Rackwitz ◽  
Michael Krumrey ◽  
Christian Laubis ◽  
Frank Scholze ◽  
Vasile-Dan Hodoroaba

Author(s):  
Klaus-Ruediger Peters

A new generation of high performance field emission scanning electron microscopes (FSEM) is now commercially available (JEOL 890, Hitachi S 900, ISI OS 130-F) characterized by an "in lens" position of the specimen where probe diameters are reduced and signal collection improved. Additionally, low voltage operation is extended to 1 kV. Compared to the first generation of FSEM (JE0L JSM 30, Hitachi S 800), which utilized a specimen position below the final lens, specimen size had to be reduced but useful magnification could be impressively increased in both low (1-4 kV) and high (5-40 kV) voltage operation, i.e. from 50,000 to 200,000 and 250,000 to 1,000,000 x respectively.At high accelerating voltage and magnification, contrasts on biological specimens are well characterized1 and are produced by the entering probe electrons in the outmost surface layer within -vl nm depth. Backscattered electrons produce only a background signal. Under these conditions (FIG. 1) image quality is similar to conventional TEM (FIG. 2) and only limited at magnifications >1,000,000 x by probe size (0.5 nm) or non-localization effects (%0.5 nm).


Author(s):  
K. Ogura ◽  
A. Ono ◽  
S. Franchi ◽  
P.G. Merli ◽  
A. Migliori

In the last few years the development of Scanning Electron Microscopes (SEM), equipped with a Field Emission Gun (FEG) and using in-lens specimen position, has allowed a significant improvement of the instrumental resolution . This is a result of the fine and bright probe provided by the FEG and by the reduced aberration coefficients of the strongly excited objective lens. The smaller specimen size required by in-lens instruments (about 1 cm, in comparison to 15 or 20 cm of a conventional SEM) doesn’t represent a serious limitation in the evaluation of semiconductor process techniques, where the demand of high resolution is continuosly increasing. In this field one of the more interesting applications, already described (1), is the observation of superlattice structures.In this note we report a comparison between secondary electron (SE) and backscattered electron (BSE) images of a GaAs / AlAs superlattice structure, whose cross section is reported in fig. 1. The structure consist of a 3 nm GaAs layer and 10 pairs of 7 nm GaAs / 15 nm AlAs layers grown on GaAs substrate. Fig. 2, 3 and 4 are SE images of this structure made with a JEOL JSM 890 SEM operating at an accelerating voltage of 3, 15 and 25 kV respectively. Fig. 5 is a 25 kV BSE image of the same specimen. It can be noticed that the 3nm layer is always visible and that the 3 kV SE image, in spite of the poorer resolution, shows the same contrast of the BSE image. In the SE mode, an increase of the accelerating voltage produces a contrast inversion. On the contrary, when observed with BSE, the layers of GaAs are always brighter than the AlAs ones , independently of the beam energy.


1978 ◽  
Vol 115 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Minoo Hojjatzadeh

SummaryTwenty-three species of the Family Discoasteraceae Vekshina, 1959 recovered from 18 samples of the Blue Clay at Fort Chambray, Gozo, and 31 samples from Fomm-Ir-Rih Bay, Malta, have been studied under light and scanning electron microscopes. Fourteen Middle Miocene species are reviewed, their stratigraphical ranges and importance as marker species discussed. Nine species are described as new. On the basis of the discoaster species present, a Middle Miocene age (NN.6 Discoaster exilis Zone – NN.7 Discoaster kugleri Zone) for the Blue Clay in Malta and Gozo is suggested.


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