Page 42 - Sensors and Control Systems in Manufacturing

The Role of Sensors in the 21st Century
Cell control 7

Work station controller
CPU and memory
Disk controller Work station
system software
Serial communications
Parallel I/O Local data base
Time and date Disk storage
CRT terminal
Auxiliary sensors
– Safety sensors
– Tool setting
– Adaptive control
Controller
Tray transport Swing clamp
Controller
and buffering
Vise
Materials
Sense switch
handling interface
Automated fixturing
Industrial robot NC machining center
FIGURE 1.3 A computer-controlled manufacturing system.

1.3 Photo Sensing Fluorescence in Genome Sequencing
The sequencing of DNA molecules began in the 1970s with develop-
ment of the Maxam-Gilbert method, and later the Sanger method.
Originally developed by Frederick Sanger in 1975, most DNA
sequencing that occurs in medical and research laboratories today is
performed using sequencers employing variations of the Sanger
method. Termed the chain-termination method, it involves a reaction
where chain-terminator nucleotides are labeled with fluorescent
dyes, combined with fragmented DNA, DNA sequencing primers,
and DNA polymerase. Each nucleotide in the DNA sequence is
labeled with a different dye color, and a chromatogram is produced,
with each color representing a different letter in the DNA code—A, T,
C, or G. Advances in sequencing technology and computer program-
ming enabled relatively fast and cost-efficient DNA sequencing.
However, sequencing of entire genomes of organisms was difficult
and time consuming. At the time the Human Genome Project was
officially started in 1990, it was thought that sequencing the human
genome would take 15 years. The sequence was released in 2003,
although some gaps still exist. The estimated project cost for the entire
Human Genome Project was around $3 billion, although this figure
represents a wide range of scientific activities that went into the
project, not exclusively genome sequencing. Optimally, current
sequencers are able to sequence approximately 2.8 million base pairs