sensitivity
Here: responsiveness or susceptibility to UV radiation.
S
significance
We speak of a significant difference when we wish to express the probability of error according to scientific or statistical standards. Consequently, a high significance expresses a clear measuring result with a low probability of error.
silicon
Strictly speaking, the material silicon is actually chemically a polyorganosiloxane. ‘Silicons’ describes a group of synthetic polymers which are extremely water-repellent. Silicon sealing rings have a very high temperature resistance but are not very resistant to oils, alkalis, acids or fats.
solarisation
here: Owing to the high energy of the UV radiation as well as the process-related deposit build-up on the inside of the quartz tube, the reaction-chamber material increasingly loses the ability to transmit UV radiation. This effect is called solarisation.
spectrophotometer
A radiometer for determining the permeability of media to various wavelengths of the optical rays spectrum.
spores (biol.)
Protozoa, algae, mosses, some bacteria, and especially (mould-) fungi form spores for asexual reproduction and dispersal. Because they have practically no metabolism, they can live for a very long time, even in especially hostile circumstances. Once they find a favourable environment, they become active again and reproduce.
staphylococci
These are non-motile Gram-positive bacteria from the cocci family arranged in grape-like clusters. Staphylococcus aureus (MRSA) in particular has achieved a dubious notoriety owing to its increasing resistance to antibiotics. Staphylococci have only low UVC resistance. Depending on the study and the staphylococcus species in question, the LD90 values for airborne organisms are in some cases significantly below 1.0 mJ/cm2.
streptococci
Like lactobacilli and enterococci, streptococci (sci. classification streptococcaceae) belong to the family of lactic-acid bacteria populating the intestine. They are Gram-positive, anaerobic but aerotolerant pathogens arranged in chains. These potentially pathogenic bacteria are also used in fermentation processes and in the medical regeneration of intestinal flora. Like staphylococci, they exhibit very little UVC resistance, and with few exceptions (here, Streptococcus faecalis) have an average LD90 value of 3.3 mJ/cm2.