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No more scary visits to the dentist
New local developments in laser technology may make visits to the dentist quite painless in future.
Dr Johan Burger and his team at the Department of Physics recently
built the first locally produced ultra short pulse laser in Africa.
This mode-locked laser uses optical fibre technology instead of the
conventional crystal or gas media.
The picosecond high power laser pulse produced by this type of laser
lasts only a millionth of a millionth of a second. The ultra fast pulse
action also generates very little heat, which makes it ideal for use in
a dentist’s practice because the laser beam neither heats nor vibrates
the tooth. Therefore, no pain. It can also be used in eye and skin
treatments.
“We know that it works, but now we have to find out why and how it works," Dr Burger explains the road ahead.
Physicists at Stellenbosch University made a strategic decision three
years ago to place greater focus on this niche research market of ultra
short pulse optical fibre lasers within the field of photonics.
Optical laser technology has its roots in the early development of the
internet and optical telecommunication systems. Today multi-kilowatt
continuous fibre lasers are being used to cut and weld metal plates in
the automobile-manufacturing and ship-building industries.
Dr Burger hopes that the Matie version will be cheaper and will require
less maintenance to enable small manufacturers to also obtain
technically sophisticated but reliable and user-friend laser equipment.
Apart from the optical glass fibre thread that was made in France
according to the Stellenbosch researchers’ specifications, most of the
components are relatively inexpensive.
The research is supported by the National Research Foundation.
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| Photo: Currently the whole two-metre laser apparatus lies stretched out on a
workbench at the Laser Research Institute, but Dr Johan Burger and
Master’s student Alex Heidt hope to condense it into a commercially
viable tool as small and compact as a lunchbox. (Photo: Engela Duvenage)
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| Research assistant Gerhardt Coetzee and Dr Marinda Bloom in their
laboratory at the Department of Microbiology. (Photo: Engela Duvenage)
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Rooibos tea gets more kick
Have you have ever wondered how to get your Rooibos tea extra strong?
Dr Marinda Bloom and her team of researchers at the Department
Microbiology have found the answer.
They recently registered an international and South African patent for
a cocktail of natural food enzymes that improves the yield of the
extract obtained from this proudly South African product by up to 30%.
The cocktail is added before fermented Rooibos tea leaves are soaked in
hot water.
The project was a joint undertaking with the Agricultural Research
Council’s Infruitec-Nietvoorbij Institute and the tea producer Cape
Natural Tea Products (Pty) Ltd. The research was funded by the BioPAD
BRIC initiative.
The research has been welcomed by the local industry as the patent
holds particular benefits for the preparation of Rooibos extract. The
commercial production of Rooibos tea is limited because it is only
cultivated in South Africa. “An innovation such as this ensures a
greater yield from the same quantity of plant material," explains Dawie
de Villiers of Cape Natural Tea Products.
Rooibos extract is used in cosmetics and pharmaceutical products, soaps
and flavoured cold drinks. It is prepared by soaking fermented plant
material in hot water, after which it is dried to form a fine, aromatic
powder.
According to Dr Bloom the research addresses the low solubility of
Rooibos tea components in hot water. “Without the enzyme cocktail, only
about 20% of traditional Rooibos tea is soluble in water, compared to
as much as 40% for black tea," she explains. “Thanks to the addition of
enzymes, the Rooibos extract yield increases by more than 30% per
kilogram plant material."
Another bonus is that the enzyme cocktail does not cause a significant
loss in the valuable anitioxidant content of the extract.
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