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24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 3301-3304, Mechanical vibrations of a solar module mounting rack cause oscillations in the orientation of the module towards the sun. The resulting intensity oscillations of the incident light originate an a.c. current at the module’s terminals. We have investigated this effect in the laboratory by means of a vibration table and outdoors where wind forces induce vibrations of the mounting rack. Although the collected results are specific and restricted to our experimental set up and environmental situation we deduce that vibration induced current transients and oscillations of a solar module’s output most often will be the dominant origin of distortion in the low frequency regime.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 3684-3687, We have investigated the reaction of photovoltaic cells to external electromagnetic fields in a frequency range of 10 Hz to 1 GHz. Outdoor recordings of received RF noise from the ambient were sampled for different solar cells and modules and compared with the reception of a simple whip antenna which represents a monopole for electromagnetic fields. Additionally in the laboratory well defined signals were generated and their reception was investigated depending on geometrical factors of the cells, such as orientation, size and distance. Cells, partly processed silicon wafers and patch antennas of equivalent dimensions were investigated. Two antenna models, namely dipole and patch configuration, are compared with the experimental findings. It was found that the gain in the investigated frequency range increases essentially linear with the cell area similar to patch antennas. A crystalline silicon cell of 100 cm2 has almost the same signal amplification as an 83 cm long whip antenna remaining coarsely constant over the whole frequency range. For narrow frequency bands however the signal attenuation or amplification is strongly modified by the dipole behavior caused by the front metal grid.

Die in der Hormon-Replacement-Therapie (HRT) zur Linderung postmenopausaler Beschwerden eingesetzten Sexualsteroide können ebenfalls Einfluss auf die Stimme nehmen. Da bei den Progestagenkomponenten solcher in der HRT angewandten Medikamente auch Substanzen zum Einsatz kommen, die nachweislich eine androgene Partialwirkung haben, wurden über einen Zeitraum von 2 Jahren die Auswirkungen auf die Stimme von Kliogest und Klimodien untersucht, zwei Präparate, die in der HRT angewandt werden, jedoch qualitativ unterschiedliche Progestagenkomponenten enthalten. Kliogest enthält Norethisteronacetat, ein Progestagenderivat mit partieller Androgenwirkung, Klimodien ein Progestagenderivat mit antiandrogener Potenz. Dabei sollte beobachtet werden, welche Auswirkungen eine HRT auf die Stimmgrundfrequenz hat, und ob Klimodien gegenüber Kliogest bezüglich der Wirkungen auf die Stimme einen Vorteil in der Behandlung von Frauen in der Postmenopause birgt. Die Ergebnisse lassen darauf schließen, dass weder in der Versuchsgruppe, deren Probandinnen Kliogest eingenommen hatten, noch in der mit Klimodien behandelten Gruppe, eine signifikante Veränderung der Stimmgrundfrequenz eingetreten ist. Daraus folgt, dass sowohl Kliogest als auch Klimodien als HRT der erwarteten "Verschlechterung" der Stimme bei postmenopausalen Frauen entgegenwirkt, und Präparate mit antiandrogener Potenz (Klimodien) gegenüber Präparaten mit androgener Partialwirkung (Kliogest) bezüglich einer Beeinflussung der Stimmgrundfrequenz keine Vorteile bergen.

Der Kehlkopf reagiert als sekundäres Geschlechtsorgan sehr sensibel auf Hormone. Die Stimme ist somit von der Balance der Geschlechtshormone im Organismus abhängig. Es zeigen sich Veränderungen bei zyklusabhängigen Schwankungen. Mit der Hochgeschwindikeitsglottographie steht eine objektive Untersuchungsmethode zur Verfügung. Die vorliegende Studie sucht nach der physiologischen Schwankungsbreite, um einen pathologischen Bereich abzugrenzen. Es werden 25 stimmgesunde Frauen im Alter von 18-25 Jahren über einen Zeitraum von 1 Monat einmal wöchentlich untersucht (HNO-Status, Stroboskopie, Hochgeschwindigkeitsglottographie, akustische Stimmanalyse, Hörprüfung, Blutabnahme, gynäkologische Anamnese). Raucherinnen und Probandinnen, die stimmbeeinflussende Medikamente einnehmen, werden ausgeschlossen. Die Probandinnen wurden in Gruppen mit und ohne Antikonzeptivum unterteilt. Bei entsprechender Auswertung der Hochgeschwindigkeitsglottographie kann man auf den Tonus der Stimmlippen schließen. Die vorliegenden Zwischenergebnisse zeigen eine Reihe von physiologischen Veränderungen, die als zyklusabhängige Schwankungen gedeutet werden können. Der Tonus steigt in der zweiten Zyklushälfte und sinkt gegen Zyklusende. Das trifft zu für Probandinnen ohne Kontrazeptivum und mit bestimmten Kontrazeptiva.

The present paper deals with the effects of the hormonal contraceptives Deposiston and Gravistat on the digestibility of dietary crude protein and on the urine excretion of nitrogen. The substances under test were given to 9 women between 18-25 years of age. The fecal and urinary nitrogen were determined in the first 2 cycles during which no contraceptives were used and also in the subsequent 3 cycles during which Deposiston and Gravistat were taken by mouth. The preperiod extended over 3 days and the sampling for 4 days. The apparent digestibility of the dietary protein was only slightly increased by the contraceptives. In the case of Deposiston it amounted to 85.0% (1st cycle) 86.0% (2nd cycle) 87.3% (3rd cycle) 87.1% (4th cycle) and 88.2% (5th cycle). Deposiston and Gravistat did not affect the urine excretion of nitrogen nor the nitrogen balance. (authors) (summaries in ENG RUS)

Renal function was investigated by isotope nephrography in 31 pregnant women with normal kidneys during various phases of pregnancy, and in 137 women on continuous contraceptive steroids (up to eight years). The semi-quantitative parameters of zum Winkel were used. It was found that the use of oral contraceptives did not lead to any change in renal function, whereas with advancing pregnancy there was distinct excretion delay on the isotope nephrogram. The results are discussed in the light of the relevant literature. Isotope nephrography appears to be a satisfactory screening test for evaluation of renal function on each side.

The relationship between high dose progestagen treatment and changes on the intravenous urogram were studied in 27 patients. For this purpose, six specific features in the urogram were examined. Our findings in the patients available to use indicate that there is no demonstrable dilatation of the renal pelves and ureters as a result of the administration of progestational substances alone. These results are discussed in relation to the relevant literature.

The relationship between high dose progesterone treatment and pregnancy and dilatation of the upper urinary tract was investigated by doing intravenous urograms on eight female rabbits. Ten features of the urogram were studied. It was concluded that the administration of sex hormones to rabbits without any mechanical change in the ureters, did not lead to urographically demonstrable dilatation of the ureters. Negative findings in pregnant animals indicate that the mechanical situation in rabbits differs from that found in human pregnancy. The results are discussed with relation to the available literature.

7 female rabbits were given subcutaneous implants of ethinyl estradiol; 2 rabbits were given subcutaneous placebo implants. Urographic tests were performed before the implantations and 3 6 and 12 weeks after the implantations. The urethral width was measured at 11 places along the upper part of each ureter. In some cases there were significant reductions in the diameter of the ureter. It was concluded that the administration of estrogens without simultaneous mechanical manipulation does not cause dilatation of the urethra. (Summary in ENG)

Changes in renal function during pregnancy were studied by sequential scintigraphy in 16 women with normal kidneys. The examinations were carried out during the first and third trimesters. Time activity curves were obtained by a computer-assisted storage and analysis procedure, using a "region of interest" technique for renal parenchyma and renal pelvis. The study included topographic changes and the evaluation of 13 semi-quantitative parameters related to the renal parenchyma and of nine parameters related to the renal pelvis. The results were demonstrated graphically. The predominantly rightsided changes in renal function during the third trimester are discussed in relation to the relevant literature.