Updating the aerodynamic resistance for subsurface ventilation

For the safety works in the mines good ventilation is one of the main requirements. For miners’ performance, the subsurface ventilation creates healthier and more hygienic conditions. Mine ventilation has always belonged to the field of mining. Moreover, nowadays the mining operations progress to greater depths, shafts are deepened and the under-level mining space develops. This brings an increase in the temperature of rocks, mine air gets heated due to the technologies used and, thus, it is necessary to pay constant attention to mine ventilation. The knowledge of aerodynamic resistance becomes crucial for the good ventilation and ventilation planning. The article describes updating and complementing the aerodynamic resistance of the powered coalface supports, dam and wind structures and auxiliary ventilation components

EXPERIMENTAL DETERMINATION OF TEMPERATURES IN SPARK GENERATED BUBBLES OSCILLATING IN WATER

The surface temperatures of the plasma core in the final stages of the first contraction phase of spark-generated bubbles oscillating under ordinary laboratory conditions in a large expanse of water are determined experimentally. The measurement method is based on an analysis of the optical radiation from the bubbles and on the assumption that the plasma core is radiating as a black-body. It is found that the maximum surface temperatures of the plasma core range 4300–8700 K

ON THE SECOND LIGHT FLASH EMITTED FROM A SPARK-GENERATED BUBBLE OSCILLATING IN WATER

The light emitted from the spark-generated bubbles oscillating in water is studied experimentally. Attention is paid to the emission of light from bubbles in the final stages of their first contraction and in the early stages of their following expansion. In some experiments, two close flashes of light were observed. The first light flash has already been studied in earlier works. In the present work, attention is paid to the second light flash. The relations between the first and second flashes of light and the size of the bubbles are studied and discussed in detail. It is assumed that these two light flashes are caused by two different processes taking place in the bubbles. The possible nature of these two processes is briefly discussed

Epigenetika u oplemenjivanju bilja

Current farming technology and advanced techniques of plant breeding are tending to enable high yields and cropping intensity, trying to alleviate the limitations of available arable land. However, rise in global population and climate changes could strain the ability to provide a stable food supply. Genetic diversity, which might be used for development of new, more resilient cultivars, could be a key for achieving better performance in agricultural production. New findings about how genes work and express, including the principles of epigenetics, could allow the advancements in breeding methods, and provide a new source of variability originating from epialleles. This paper provides a synopsis of the most significant epigenetic modifications, and particularities of plant species that impact epigenetic mechanisms, although it is mainly focused on application of epigenetics on plant breeding. Epigenetic aspects of breeding are described for increased yield in Brassica napus due to recursive selection for an epigenetic compound. Future application might be based on epigenetic recombinant inbred lines, similar to those in Arabidopsis thaliana, inhibition of DNA methylation in Oryza sativa, discovery of MSH1 system in Glycine max and Solanum lycopersicon. It also outlines the current issues and limitations of epigenetic breeding such as a lack of understanding of epigenetic mechanisms, interaction of epigenetic and stress responsive mechanisms, and the development of statistical models able to predict the impact and outcome of epigenetic modifications.Postojeće tehnologije u poljoprivredi, kao i napredne tehnike u oplemenjivanju bilja nastoje omogućiti visoke prinose i intenzitet proizvodnje, uz ublažavanje ograničenja dostupnog poljoprivrednog zemljišta. Međutim, rast populacije u svijetu, ka i klimatske promjene, mogu ugroziti mogućnost stabilne opskrbe hranom. Genetska raznolikost koju bismo mogli upotrijebiti za razvoj novih, otpornijih kultivara, mogla bi biti ključna za ostvarivanje efikasnije poljoprivredne proizvodnje. Saznanja o načinu djelovanja gene i njihovoj ekspresiji, uključujući i principe epigenetike, mogla bi omogućiti napredak oplemenjivačkih metoda i pružiti novi izvor varijabilnosti koji proizlazi od epialela. U ovom radu pružen je pregled najznačajnijih epigenetskih modifikacija, kao i specifičnosti biljnih vrsta kod kojih postoje epigenetski mehanizmi, s naglaskom na primjenu epigenetike u oplemenjivanju bilja. Epigenetsko oplemenjivanje je opisano na primjeru porasta prinosa kod uljane repice, zahvaljujući ponavljajućoj selekciji epigenetske komponente. Buduća primjena epigenetike mogla bi se zasnivati na epigenetskim rekombinantama inbred linija, kao u primjeru arabidopsisa, inhibiciji DNA metilacije kod riže, ili otkriću sistema MSH1 kod soje i paradajza. Ovaj rad ističe aktualna pitanja u vezi epigenetskog oplemenjivanja, kao i njegova ograničenja, poput nedovoljnog razumijevanja epigenetskih mehanizama, interakcije epigenetskih faktora i mehanizama odgovora na stres, kao i nedostatka razvoja statističkih metoda u predviđanju utjecaja i djelovanja epigenetskih modifikacija

Einsiedelnské kaple v Čechách a vliv bádenských markrabat

https://old.fpe.zcu.cz/export/sites/fpe/khi/Dokumenty/BOH/BOH_2_2021.pdfThe paper discuss the propagation of the cult of the Virgin of Einsiedeln in the Bohemian lands during the 17th and 18th centuries. Among the patrons of cult, the margraves of Baden-Baden played a crucial role which is shown on the examples from their manors, especially on the case of Johann Georg Track who, so the argument of the paper, translated the cult from Rastatt (Baden) to his birthplace in Bohemia