To cite this version:DAbstract. The atmospheric pressure dielectric barrier discharge burning in nitrogen with small admixture of hexamethyldisiloxane (HMDSO) was used for the deposition of thin organosilicon films. The thin films were deposited on glass, silicon and polycarbonate substrates, the substrate temperature during the deposition process was elevated up to values within the range 25 • C -150 • C in order to obtain hard SiO x -like thin films. The properties of the discharge were studied by means of optical emission spectroscopy and electrical measurements. The deposited films were characterised by Rutherford backscattering and elastic recoil detection methods, x-ray photoelectron spectroscopy, infrared spectroscopy measurements, ellipsometry and depth sensing indentation technique. It was found that the films properties depend significantly on substrate temperature at deposition. An increase of substrate temperature from 25 • C to 150 • C leads to an increase of film hardness from 0.4 GPa to 7 GPa and the film chemical composition changes from CH x Si y O z to SiO x H y . The films were transparent in visible range.

This paper describes theoretical calculation of the terminal velocity of falling cat, taking the air drag into account. The results show that a fall from the seventh floor is critical for the cat so we introduce a new quantity called the ‘coefficient of the cat’s fear’ during free fall. A subsequent experiment with a model of a cat carrying the accelerometer confirmed this conclusion. This calculation and experiment can act as a strong motivational factor during introductory physics courses.

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This paper describes the design of a low-cost radon detector that can easily be fabricated in large quantities for the purposes of earthquake prediction. The described detector can also be used for monitoring radon levels in houses because high radon levels pose a great health risk. A very simple air-ionization chamber for alpha particles was used, considering the experimental results. Chamber current-sensing circuitry is also suggested, and an Internet of Things (IoT) sensor grid is described. The main advantages of this detector are the low cost, low power consumption, and complete elimination of high-voltage power sources. The minimum detectable activity achieved with the proposed detector for one measurement was around 50 Bq · m − 3 , with time of measurement comparable to that featured on commercial devices, while the price of the described detector is one order of magnitude lower.

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