Utilization of the Validated Windshield Material Model in Simulation of Tram to Pedestrian Collision.

The rail industry has been significantly affected by the passive safety technology in the last few years. The tram front-end design must fulfill the new requirements for pedestrian passive safety performance in the near future. The requirements are connected with a newly prepared technical guide "Tramway front end design" prepared by Technical Agency for ropeways and Guided Transport Systems. This paper describes research connected with new tram front-end design safe for pedestrians. The brief description of collision scenario and used human-body model "Virthuman" is provided. The numerical simulations (from field of passive safety) are supported by experiments. The interesting part is the numerical model of the tram windshield experimentally validated here. The results of simulations are discussed at the end of paper.

Magnetically modified biochar for organic xenobiotics removal.

Large amounts of biochar are produced worldwide for potential agricultural applications. However, this material can also be used as an efficient biosorbent for xenobiotics removal. In this work, biochar was magnetically modified using microwave-synthesized magnetic iron oxide particles. This new type of a magnetically responsive biocomposite material can be easily separated by means of strong permanent magnets. Magnetic biochar has been used as an inexpensive magnetic adsorbent for the removal of water-soluble dyes. Five dyes (malachite green, methyl green, Bismarck brown Y, acridine orange and Nile blue A) were used to study the adsorption process. The dyes adsorption could be usually described with the Langmuir isotherm. The maximum adsorption capacities reached the value 137 mg of dye per g of dried magnetically modified biochar for Bismarck brown Y. The adsorption processes followed the pseudo-second-order kinetic model and the thermodynamic studies indicated spontaneous and endothermic adsorption. Extremely simple magnetic modification of biochar resulted in the formation of a new, promising adsorbent suggested for selected xenobiotics removal.

Why has nature invented three stop codons of DNA and only one start codon?

We examine the standard genetic code with three stop codons. Assuming that the synchronization period of length 3 in DNA or RNA is violated during the transcription or translation processes, the probability of reading a frameshifted stop codon is higher than if the code would have only one stop codon. Consequently, the synthesis of RNA or proteins will soon terminate. In this way, cells do not produce undesirable proteins and essentially save energy. This hypothesis is tested on the AT-rich Drosophila genome, where the detection of frameshifted stop codons is even higher than the theoretical value. Using the binomial theorem, we establish the probability of reading a frameshifted stop codon within n steps. Since the genetic code is largely redundant, there is still space for some hidden secondary functions of this code. In particular, because stop codons do not contain cytosine, random C → U and C → T mutations in the third position of codons increase the number of hidden frameshifted stops and simultaneously the same amino acids are coded. This evolutionary advantage is demonstrated on the genomes of several simple species, e.g. Escherichia coli.