scholarly journals Precise Evaluation of Charging Effect on SiO2 Particles by Simulation of Holograms

2002 ◽  
Vol 43 (3) ◽  
pp. 474-477
Author(s):  
Yoshitaka Aoyama ◽  
Young-Gil Park ◽  
Chang-Woo Lee ◽  
Daisuke Shindo
Author(s):  
K. Ogura ◽  
T. Suzuki ◽  
C. Nielsen

In spite of the complicated specimen preparation, Transmission Electron Microscopes (TEM) have traditionally been used for the investigation of the fine grain structures of sintered ceramics. Scanning Electron Microscopes (SEM) have not been used much for the same purpose as TEM because of poor results caused by the specimen charging effect, and also the lack of sufficient resolution. Here, we are presenting a successful result of high resolution imaging of sintered alumina (pure Al2O3) using the Specimen Heated and Electron Beam Induced Conductivity (SHEBIC) method, which we recently reported, in an ultrahigh resolution SEM (UHR-SEM). The JSM-6000F, equipped with a Field Emission Gun (FEG) and an in-lens specimen position, was used for this application.After sintered Al2O3 was sliced into a piece approximately 0.5 mm in thickness, one side was mechanically polished to get a shiny plane for the observation. When the observation was started at 20 kV, an enormous charging effect occured, and it was impossible to obtain a clear Secondary Electron (SE) image (Fig.1).


Author(s):  
Keiichi Tanaka

With the development of scanning electron microscope (SEM) with ultrahigh resolution, SEM became to play an important role in not only cytology but also molecular biology. However, the preparation methods observing tiny specimens with such high resolution SEM are not yet established.Although SEM specimens are usually coated with metals for getting electrical conductivity, it is desirable to avoid the metal coating for high resolution SEM, because the coating seriously affects resolution at this level, unless special coating techniques are used. For avoiding charging effect without metal coating, we previously reported a method in which polished carbon plates were used as substrate. In the case almost all incident electrons penetrate through the specimens and do not accumulate in them, when the specimens are smaller than 10nm. By this technique some biological macromolecules including ribosomes, ferritin, immunoglobulin G were clearly observed.Unfortunately some other molecules such as apoferritin, thyroglobulin and immunoglobulin M were difficult to be observed only by the method, because they had very low contrast and were easily damaged by electron beam.


Author(s):  
Agnieszka Napierała ◽  
Jerzy Błoszyk

AbstractThe necessity of monitoring changes occurring in soil compels us to look for new methods that will allow easy and precise evaluation of the soil quality in a given area. One proposed method is the maturity index (MI) – an index that is based on the distribution of species along the r-to-K continuum in examined populations. In this study, mites from the suborder Uropodina (Acari: Mesostigmata) were examined for their appropriateness in MI-based assessments of soil quality. The first aim of the study was to establish the criteria on the basis of which the evaluation of the r-to-K reproductive strategies was conducted for Uropodina in the examined communities. The second aim was to evaluate the performance of the maturity index of communities of Uropodina as indicator of human-caused disturbance in five areas that are legally protected in Poland. The selected areas were: Białowieża Primeval Forest, Gorce National Park, and three nature reserves: Jakubowo, Las Grądowy nad Mogilnicą, and Cisy Staropolskie im. Leona Wyczółkowskiego. We found that as many as 68 out of the 96 analyzed Uropodina species in Poland are K-stategists. The highest values of the maturity index were recorded for the nature reserves Cisy Staropolskie im. Leona Wyczółkowskiego and the Białowieża Primeval Forest.


The Analyst ◽  
2021 ◽  
Author(s):  
Chang Shu ◽  
Tengfei Li ◽  
Duo Li ◽  
Zhong-Qiu Li ◽  
Xing-Hua Xia

Protein drugs showing strong pharmaceutical activity, high specificity, low toxicity and side effects, have drawn extensive attention from the field of life science and medicine. Precise evaluation of the function...


1995 ◽  
Vol 50 (4-5) ◽  
pp. 381-387 ◽  
Author(s):  
Jürgen Kintrup ◽  
Harald Züchner

Abstract X-ray photoelectron spectroscopy (XPS) has been carried out to study the reaction of differently prepared palladium samples (solid and film Pd) with atmospheric oxygen. A careful curve fitting of the measured Pd-3d5/2 peak allows to separate the Pd-3d5/2 peak for Pd in surface PdO from the dominant Pd-3d5/2 peak of the non-oxidized bulk palladium and to determine the chemical shift of the "oxidized" Pa line with high accuracy. Differences in the chemical shifts for the surface PdO on solid and film palladium are explained by a different charging caused by the photoelectric effect in XPS measurements. The smaller charging effect observed for film palladium as compared to solid palladium indicates a stronger oxygen bonding to the (rougher) film palladium. The strong Pd-O bonding seems to be an essential reason for the reduced hydrogen-permeability of film palladium compared to solid palladium


2016 ◽  
Vol 18 (43) ◽  
pp. 30079-30085 ◽  
Author(s):  
Y. Lu ◽  
K. Wang ◽  
F.-R. Chen ◽  
W. Zhang ◽  
M. L. Sui

We report the migration and segregation behaviors of Au atoms in solution during real time, by exploiting a charging effect in a dilute HAuCl4 water solution under electron irradiation, to allow the growth kinetics of Au nanoparticles to be successfully controlled.


2015 ◽  
Vol 27 (7) ◽  
pp. 1012 ◽  
Author(s):  
C. E. R. Ferreira ◽  
D. B. Sávio ◽  
A. C. Guarise ◽  
M. J. Flach ◽  
G. D. A. Gastal ◽  
...  

Heterospermic AI is commonly used in swine despite preventing precise evaluation of individual boar fertility. The present study compared the contribution of four boars (A, B, C and D) for reproductive performance and for paternity using homospermic and heterospermic (AB, AC, AD, BC, BD and CD) AI (n = 204 for homospermic AI; n = 307 for heterospermic AI). Blood samples from the four boars, from all sows inseminated with heterospermic doses and from the umbilical cords of their piglets, as well as tissue smears from mummified fetuses, were genotyped using single nucleotide polymorphisms (SNPs). Differences among boars were detected for the in vitro oocyte penetration rate and for the number of spermatozoa per oocyte (P < 0.05), but not for sperm motility, mitochondrial functionality and integrity of the membrane, acrosome and DNA (P > 0.05). Homospermic and heterospermic AI resulted in similar (P > 0.05) farrowing rates (90.5% and 89.9%, respectively) and total litter size (12.4 ± 0.4 and 12.7 ± 0.7, respectively). Farrowing rate was lower for Boar B than for Boar C (P < 0.05), but no other differences in reproductive performance among boars were observed with homospermic AI. The SNPs determined the paternity of 94.2% of the piglets sired by heterospermic AI. In the AC pool, paternity contribution per boar was similar (P > 0.05), but differences between boars occurred in all other pools (P < 0.05). Boar D achieved the greatest paternity contribution in all pools and parity categories (nearly 60%), whereas Boar B sired the fewest piglets (at most 40%). Reproductive performance was similar with homospermic and heterospermic AI, but differences in performance among boars undetected with homospermic AI were only evident after genotyping the piglets sired through heterospermic AI.


Oncotarget ◽  
2018 ◽  
Vol 9 (75) ◽  
pp. 34132-34141 ◽  
Author(s):  
Soyoko Morimoto ◽  
Fumihiro Fujiki ◽  
Kenta Kondo ◽  
Hiroko Nakajima ◽  
Yoshiki Kobayashi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document