Andrew Rusek

An examination of the effect of an AC pulsed electric field on cell mortality in SWLA-2 hybridomas

This work describes the initial experimental setup and results involving the percentage cell lysis in SWLA-2 murine hybridomas produced by AC electric field pulses of varying amplitudes and pulse widths. Cells were cultured and separate samples examined at 24 hours. The frequency, pulse width and peak-to-peak voltage were varied. AC electric fields producing at least 1 V across the cell membrane appear to be more effective in producing cell lysis than similar fields producing lower membrane voltages. Additionally, higher frequencies, in the 10 kHz range, appear to be more effective than lower frequencies at membrane voltages above 1 V in producing cell lysis.

Self-Discharging of Lead-Acid Batteries

ABSTRACT The US Army has recently transitioned to using“maintenance free” batteries in its ground vehicles toincrease the over-all vehicle readiness. Using lead-calcium alloy grids in place of the “reduced maintenance”design decreases water loss. This loss of water is knownto be a measure of the battery self discharge. In thisstudy, the charging of SLI batteries was examined over arange of operating temperatures as a means forcharacterizing the self-discharge rate as a function ofbattery voltage and temperature. The battery responsewas modeled analytically. Current activities are directedtoward achieving a better description of the battery self-discharge over extreme environmental conditions. INTRODUCTION The self-discharge of lead-acid starting, lighting andignition (SLI) batteries is a major factor influencingvehicle readiness. The reason for this is that militaryvehicles tend to be stored for extended periods of timebefore being brought back into service. These longperiods allow sufficient self-discharge to take placeresulting in a high probability that the vehicle will fail tostart. Since self-discharge is a naturally occurringphenomena in lead-acid batteries, there exists a need fordeveloping a better understanding of this effect and for generating some quantitative methods for predictingits consequences [1].

Reflectometers, Time-Domain

Time-domain reflectometry (TDR ) is one of the most useful methods of analyzing signal integrity in transmission media. This includes conventional “hardwired” devices such as cables, microstrip transmission lines, and other transmission paths found in radiofrequency, microwave, and high-speed digital circuits and systems. This article describes the basic concepts of the TDR technique as well as associated with a related technique: time-domain transmission (TDT ). Through the course of this article, conventional TDR signal measurements related to various transmission-line loads are demonstrated and discussed. In addition, a differential TDR system is presented. Finally, TDR /TDT test results illustrating reflections due to parasitic effects, as well as normalization techniques in modern TDR systems, are described. Keywords: characteristic impedance; signal integrity; reflection; time-domain reflectometry; transmission lines