A High-Performance Low-Ringing Ultrawideband Monocycle Pulse Generator

2012 ◽  
Vol 61 (1) ◽  
pp. 261-266 ◽  
Author(s):  
Tian Xia ◽  
Anbu Selvam Venkatachalam ◽  
Dryver Huston
2019 ◽  
Vol 9 (3) ◽  
pp. 26
Author(s):  
P. LOKESH ◽  
V. THRIMURTHULU ◽  
PRIYA L. MIHIRA ◽  
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◽  
...  

2019 ◽  
Vol 18 ◽  
pp. 153303381882109
Author(s):  
Bratko Filipič ◽  
Klemen Rihar ◽  
Dunja Exel Gregorič ◽  
Lidija Gradišnik ◽  
Adriana Pereyra ◽  
...  

Macrophages play key role in host defense and tissue repair, and thus understanding regulation of their function is important. For instance, our previous results have shown that in chicken macrophage system (CoMA cell line), application of a pulse of electromagnetic fields of frequencies 0.618, 1.054, 5.229, and 100.414 kHz induces production of interferon γ-like molecules. In this study, we have shown that the electromagnetic field of 100.414 kHz is the most effective in inducing synthesis of chicken interferon γ and chicken interferon γ-like molecules in CoMA cells, especially when combined with Lens culinaris agglutinin and 10% phosphate-buffered saline washouts of different Holocene minerals. A 2-minute pulse of electromagnetic field was produced by Defender’s pulse generator. Both chicken interferon γ and chicken interferon γ-like molecules from the cell supernatant were evaluated by an antiviral assay and were also analyzed with reverse-phase high-performance liquid chromatography on Phenomenex, Aeris peptide columns. Our results show that application of a single inducing factor ( Lens culinaris agglutinin, 100.414 kHz electromagnetic field, 10% phosphate buffer saline washout) or combined usage of 2 of them moderately stimulated production of chicken interferon γ-like molecules (from 1.550 to 48.028 IU/mL), whereas the combination of 10% phosphate-buffered saline washout of Koprivnica rock + Lens culinaris agglutinin + 100.414 kHz/9 V resulted in an output of 162.122 IU/mL. Hence, we may conclude that a combined use of electromagnetic field, Holocene minerals, and Lens culinaris agglutinin greatly stimulates synthesis of chicken interferon γ-like molecules in CoMA cells.


Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).


Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.


Author(s):  
John W. Coleman

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.


Author(s):  
J W Steeds ◽  
R Vincent

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.


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