Measuring the length of hydrodynamically injected plugs in capillary electrophoresis using the electrical current monitoring

2006 ◽  
Vol 27 (21) ◽  
pp. 4166-4173 ◽  
Author(s):  
Guillaume L. Erny ◽  
Alejandro Cifuentes
Keyword(s):  
Capillary Electrophoresis ◽  
Electrical Current ◽  
Current Monitoring

Improved Capillary Electrophoresis Separation Using a Capillary Bundle

2008 ◽  
Author(s):  
Nam-Trung Nguyen ◽  
Yi Sun ◽  
Yien-Chian Kwok
Keyword(s):  
Capillary Electrophoresis ◽  
Joule Heating ◽  
Heat Dissipation ◽  
Electrical Current ◽  
Electric Resistance ◽  
Separation Channel ◽  
Cross Sectional ◽  
Narrow Channels ◽  
Capillary Bundle ◽  
Separation Columns

Joule heating is an undesirable effect in capillary electrophoresis (CE). The heat generated by the electrical current leads to a temperature gradient along the separation channel and consequently affects the separation quality. Since the heat is inversely proportional to the electric resistance of the separation column, increasing the electric resistance can reduce the effect of Joule heating. Currently, due to the limit of fabrication technique and detection apparatus, the typical dimensions of CE microchannels are in the range of 50 μm to 200 μm. In this paper, we describe the method of reducing the cross-sectional area of the separation channel and increasing the channel’s surface for better heat dissipation. A photonic crystal fiber (PCF) is a bundle of extremely narrow channels, which ideally work as separation columns. The PCF was simply encapsulated in a polymethylmethacrylate (PMMA) microchannel right after a T-shaped injector. CE was simultaneously but independently carried out in 54 narrow capillaries, each capillary with diameter of 3.7 μm. The capillary bundle could sustain high electric field strength up to 1000 V/cm due to efficient heat dissipation, thus faster and enhanced separation was attained.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

Sign in / Sign up

Export Citation Format

Share Document