Switzerland

Johannes KELLER (19)

City/Region: Weinfelden
E-mail: johanneskeller@yahoo.de
Hobbies: Ancient music, Computer programming
Career: Musician; Physician
School: Kantonsschule Frauenfeld

The influence of the quill-shape on the harpsichord sound

There is an amazing variety of timbres in the diversity of harpsichords, a baroque keyboard instrument. This variety is mainly caused by the features of the soundboard and the proportions in general. This paper shows for the first time in a scientific way that also the shape of the quill influences the timbre of a harpsichord. The quill is the central element in the harpsichord mechanics because it plucks the string like an artificial fingernail. An important part of the paper is the development of a FFT-program (Fast Fourier Transformation) for the physical analysis, written in C++ / OpenGL. So, the analysis - software could be ideally adapted to the high requirements of the harpsichord sound. Over 20 different quill shapes were examined to make the results as detailed as possible. The results of the measurements help a harpsichord maker or a harpsichordist to make quills for a certain desired timbre (for example: peaked and rather long quills for a French tonality). In addition, the paper sums up the experience and opinions of several specialists in the field of harpsichord making and playing.
 

Tobias BRUDERER (19)

City/Region: Goldach
E-mail: tobias@cevi.ch
Hobbies: Sports (Snowboarding, Swimming, Kayak, Inlineskating, Yoseikan), Playing music (keyboard, drums, didgeridoo), Voluntary work
Career: Environmental Scientist
School: Kantonsschule am Burggraben

Wito TRAUB (19)

City/Region: St. Gallen
E-mail: w.traub@gmx.ch
Hobbies: Sports (e.g. Skiing, Playing football, Surfing)
Career: Physicist
School: Kantonsschule am Burggraben

Effects of electric and magnetic fields

The common use of electrical and electronic appliances and the increasing use of electromagnetic waves for data transmission generate electromagnetic fields. Opinions are divided on the possible effects of these weak fields on living beings. We have investigated the influence of such fields on two model organisms, Bacillus megaterium (a bacterium) and Drosophila melanogaster (fruit fly) by determining replication rates. In addition, the cell lengths of B. megaterium and the formation of intracellular storage polymers (as a stress indicator) were determined. The irradiation of the fruit flies by a low frequency alternating magnetic field (80 µT at 50 Hz) resulted in an increase in the reproduction rate. B. megaterium showed an enhanced replication rate as well. A slight increase in the average cell length was also observed. The content of intracellular storage polymers was not influenced. The exposure of B. megaterium to a low frequency electric field (620 V/m at 50 Hz) led to an increase in the formation of colonies. Increases in replication rates as well as a reduced storage polymer formation were observed upon exposure to a weak high frequency electromagnetic field (0.4 V/m at 960.8 MHz). In conclusion, several effects of electromagnetic fields on living beings have been demonstrated.