A Simple Low-Voltage All MOS Linear-dB AGC/ Multiplier Circuit

Author(s):  
R.A. Brannen ◽  
H. Elwan ◽  
M. Ismail
2020 ◽  
Vol 10 (22) ◽  
pp. 8254
Author(s):  
Javed Ahmad ◽  
Mohammad Zaid ◽  
Adil Sarwar ◽  
Chang-Hua Lin ◽  
Shafiq Ahmad ◽  
...  

In this paper, a new transformerless high voltage gain dc-dc converter is proposed for low and medium power application. The proposed converter has high quadratic gain and utilizes only two inductors to achieve this gain. It has two switches that are operated simultaneously, making control of the converter easy. The proposed converter’s output voltage gain is higher than the conventional quadratic boost converter and other recently proposed high gain quadratic converters. A voltage multiplier circuit (VMC) is integrated with the proposed converter, which significantly increases the converter’s output voltage. Apart from a high output voltage, the proposed converter has low voltage stress across switches and capacitors, which is a major advantage of the proposed topology. A hardware prototype of 200 W of the proposed converter is developed in the laboratory to validate the converter’s performance. The efficiency of the converter is obtained through PLECS software by incorporating the switching and conduction losses.


2014 ◽  
Vol 2 (3) ◽  
pp. 124-127
Author(s):  
Behzad Ghanavati ◽  
Enayatollah Taghavi Moghaddam

Author(s):  
Marek Malecki ◽  
J. Victor Small ◽  
James Pawley

The relative roles of adhesion and locomotion in malignancy have yet to be clearly established. In a tumor, subpopulations of cells may be recognized according to their capacity to invade neighbouring tissue,or to enter the blood stream and metastasize. The mechanisms of adhesion and locomotion are themselves tightly linked to the cytoskeletal apparatus and cell surface topology, including expression of integrin receptors. In our studies on melanomas with Fluorescent Microscopy (FM) and Cell Sorter(FACS), we noticed that cells in cultures derived from metastases had more numerous actin bundles, then cells from primary foci. Following this track, we attempted to develop technology allowing to compare ultrastructure of these cells using correlative Transmission Electron Microscopy(TEM) and Low Voltage Scanning Electron Microscopy(LVSEM).


Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.


Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.


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